Surface metallization of glass fiber(GF)/polyetheretherketone(PEEK)[GF/PEEK] is conducted by coating copper using electroplating and magnetron sputtering and the properties are determined by X-ray diffraction(XRD), sc...Surface metallization of glass fiber(GF)/polyetheretherketone(PEEK)[GF/PEEK] is conducted by coating copper using electroplating and magnetron sputtering and the properties are determined by X-ray diffraction(XRD), scanning electron microscopy(SEM), and electron backscatter diffraction(EBSD).The coating bonding strength is assessed by pull-out tests and scribing in accordance with GB/T 9286-1998.The results show that the Cu coating with a thickness of 30 μm deposited on GF/PEEK by magnetron sputtering has lower roughness, finer grain size, higher crystallinity, as well as better macroscopic compressive stress,bonding strength, and electrical conductivity than the Cu coating deposited by electroplating.展开更多
Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were investigated.As...Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were investigated.As the sputtering power increases from 15 to 60 W,the Co thin films transition from an amorphous to a polycrystalline state,accompanied by an increase in the intercrystal pore width.Simultaneously,the resistivity decreases from 276 to 99μΩ·cm,coercivity increases from 162 to 293 Oe,and in-plane magnetic aniso-tropy disappears.As the sputtering pressure decreases from 1.6 to 0.2 Pa,grain size significantly increases,resistivity significantly de-creases,and the coercivity significantly increases(from 67 to 280 Oe),which can be attributed to the increase in defect width.Corres-pondingly,a quantitative model for the coercivity of Co thin films was formulated.The polycrystalline films sputtered under pressures of 0.2 and 0.4 Pa exhibit significant in-plane magnetic anisotropy,which is primarily attributable to increased microstress.展开更多
This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide(ITO)target.The positive ion energies exhibit an upward trajectory with increasing RF power,att...This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide(ITO)target.The positive ion energies exhibit an upward trajectory with increasing RF power,attributed to heightened plasma potential and initial emergent energy.Simultaneously,the positive ion flux escalates owing to amplified sputtering rates and electron density.Conversely,negative ions exhibit broad ion energy distribution functions(IEDFs)characterized by multiple peaks.These patterns are clarified by a combination of radiofrequency oscillation of cathode voltage and plasma potential,alongside ion transport time.This elucidation finds validation in a one-dimensional model encompassing the initial ion energy.At higher RF power,negative ions surpassing 100 e V escalate in both flux and energy,posing a potential risk of sputtering damages to ITO layers.展开更多
The mechanical and frictional properties of ta-C coatings deposited on the substrate surface affect applications in the field of cutting tools and wear-resistant components.In this paper,the effect of bias parameters ...The mechanical and frictional properties of ta-C coatings deposited on the substrate surface affect applications in the field of cutting tools and wear-resistant components.In this paper,the effect of bias parameters on the performance of ta-C coatings was investigated based on high power impulse magnetron sputtering(HiPIMS)technology.The results show that bias voltage has a significant effect on the deposition rate,structure,and wear resistance of the coating.In the range of bias voltage−50 V to−200 V,the ta-C coating performance was the best under bias voltage−150 V.The thickness reached 530.4 nm,the hardness value reached 35.996 GPa,and the bonding force in-creased to 14.2 N.The maximum sp3 bond content was 59.53% at this condition.展开更多
Al_(1-x)In_(x)N, a Ⅲ-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap e...Al_(1-x)In_(x)N, a Ⅲ-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap energy varies from 0.7 eV to 6.2 eV, which shows great potential for application in photodetectors. Here, we report the fabrication and performance evaluation of integrated Al_(1-x)In_(x)N on a free-standing GaN substrate through direct radio-frequency magnetron sputtering.The optical properties of Al_(1-x)In_(x)N will be enhanced by the polarization effect of a heterostructure composed of Al_(1-x)In_(x)N and other Ⅲ-nitride materials. An Al_(1-x)In_(x)N/Ga N visible-light photodetector was prepared by semiconductor fabrication technologies such as lithography and metal deposition. The highest photoresponsivity achieved was 1.52 A·W^(-1)under 365 nm wavelength illumination and the photodetector was determined to have the composition Al0.75In0.25N/GaN.A rise time of 0.55 s was observed after transient analysis of the device. The prepared Al_(1-x)In_(x)N visible-light photodetector had a low dark current, high photoresponsivity and fast response speed. By promoting a low-cost, simple fabrication method,this study expands the application of ternary alloy Al_(1-x)In_(x)N visible-light photodetectors in optical communication.展开更多
To achieve high microwave permeability in wide-band for the micron-thick magnetic films,[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer structure was proposed by co-sputtering Fe and FeNi to form the magnetic layers and Cr to f...To achieve high microwave permeability in wide-band for the micron-thick magnetic films,[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer structure was proposed by co-sputtering Fe and FeNi to form the magnetic layers and Cr to form the interlayers.The multilayer structure contributes to the high permeability by reducing the coercivity and diminishing out-of-plane magnetization.The maximum imaginary permeability of[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer film reaches a large value of 800 at 0.52 GHz even though its overall thickness exceeds 1μm.Besides,the magnetic resonance frequency of the multilayer film can be modulated from 0.52 to 1.35 GHz by adjusting the sputtering power of Fe from 0 to 86 W,and its bandwidth for μ’’>200(Δf) is as large as 2.0 GHz.The desirable broad Δf of magnetic permeability,which can be well fitted by the Landau-Lifshitz-Gilbert equations,is due to dual magnetic resonances originated from double magnetic phases of Fe and FeNi that are of different saturation magnetization.The micron-thick multilayer films with high permeability in extended waveband are promising candidate for electromagnetic noise suppression application.展开更多
Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency (RF) msgnetron sputtering at room temperature, The...Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency (RF) msgnetron sputtering at room temperature, The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power, The lowest resistivity achieved is 2.07 × 10^-3Ωcm at an RF power of 100W with a Hall mobility of 16cm^2V^-1s^-1 and a carrier concentration of 1.95 × 10^20 cm^-3. The films obtained are polycryetalline with a hexagonal structure and a preferred orientation along the c-axis, All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.展开更多
The CrN and Cr-Al-Si-N films were deposited on Si wafer and SUS 304 substrates by a hybrid coating system with high power impulse magnetron sputtering (HIPIMS) and a DC pulse sputtering using Cr and AlSi targets under...The CrN and Cr-Al-Si-N films were deposited on Si wafer and SUS 304 substrates by a hybrid coating system with high power impulse magnetron sputtering (HIPIMS) and a DC pulse sputtering using Cr and AlSi targets under N2/Ar atmosphere.By varying the sputtering current of the AlSi target in the range of 0-2.5 A,both the Al and Si contents in the films increased gradually from 0 to 19.1% and 11.1% (mole fraction),respectively.The influences of the AlSi cathode DC pulse current on the microstructure,phase constituents,mechanical properties,and oxidation behaviors of the Cr-Al-Si-N films were investigated systematically.The results indicate that the as-deposited Cr-Al-Si-N films possess the typical nanocomposite structure,namely the face centered cubic (Cr,Al)N nano-crystallites are embedded in the amorphous Si3N4 matrix.With increasing the Al and Si contents,the hardness of the film first increases from 20.8 GPa for the CrN film to the peak value of 29.4 GPa for the Cr0.23Al0.14Si0.07 N film,and then decreases gradually.In the meanwhile,the Cr0.23Al0.14Si0.07N film also possesses excellent high-temperature oxidation resistance that is much better than that of the CrN film at 900 or 1000 °C.展开更多
Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods. Unbalanced magnetron sputterin...Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods. Unbalanced magnetron sputtering, by producing dense secondary plasma around the substrate, provides a high ion current density. The closed-field unbalanced magnetron sputtering system (CFUBMS) has been established as a versatile technique for high-rate deposition high-quality metal, alloy, and ceramic thin films. The'key factor in the CFUBMS system is the ability to transport high ion currents to the substrate, which can enhance the formation of full dense coatings at relatively low value homologous temperature. The investigation shows that the energy of ions incidenced at the substrate and the ratio of the flux of these ions to the flux of condensing atoms are the fundamental parameters in determining the structure and properties of films produced by ion-assisted deposition processes. Increasing ion bombardment during deposition combined with increasing mobility of the condensing atoms favors the formation of a dense microstructure and a smooth surface.展开更多
TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-r...TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-ray diffraction(XRD),atomic force microscopy(AFM) and ultraviolet spectrophotometer,respectively.The results indicated that working pressure was the key deposition parameter in?uencing the TiO2 film phase composition at room temperature,which directly affected its photocatalytic activity.With increasing working pressure,the target self-bias decreases monotonously.Therefore,low temperature TiO2 phase(anatase) could be deposited with high working pressure.The anatase TiO2 films deposited with 1.4 Pa working pressure displayed the highest photocatalytic activity by the decomposition of Methyl Orange solution,which the degradation rate reached the maximum(35%) after irradiation by ultraviolet light for 1 h.展开更多
V2O5 films were prepared on silicon wafers by DC magnetron sputtering and post-annealing under various conditions. The influence of depositing and post-annealing temperatures on microstructure of V2O5 films was studie...V2O5 films were prepared on silicon wafers by DC magnetron sputtering and post-annealing under various conditions. The influence of depositing and post-annealing temperatures on microstructure of V2O5 films was studied by XRD and Raman scattering measurements. The results reveal that sputtered V2O5 films show preferred growth orientation along (001) planes and the c-axis is perpendicular to the silicon substrate surface. It is interesting to find that both the V2O5 film deposited at temperature of 511 ℃ and the one annealed at 500 ℃ exhibit desirable layer-type structure of orthorhombic symmetry. Such layer-typed V2O5 films are promising candidates for cathodes of rechargeable lithium or magnesium thin-film batteries.展开更多
A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of-50 nm in thickness on it were fabricated by magnetron sputtering. The surface morphology, composition, surface distributions of allo...A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of-50 nm in thickness on it were fabricated by magnetron sputtering. The surface morphology, composition, surface distributions of alloy elements, and lithium intercalation/de-intercalation behaviors of the fabricated films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectrometry (ICP), cyclic voltammetry (CV), and galvanostatic charge/discharge (GC) measurements. It is found that the lithium intercalation/de-intercalation behavior of the Sn film can be significantly improved by its composite with graphite. With cycling, the discharge capacity of the Sn film without composite changes from 570 mAh/g of the 2nd cycle to 270 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 90% and 95%. Nevertheless, the discharge capacity of the composite Sn/C film changes from 575 mAh/g of the 2nd cycle to 515 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 95% and 100%. The performance improvement of tin by its composite with graphite is ascribed to the retardation of the bulk tin cracking from volume change during lithium intercalation and de-intercalation, which leads to the pulverization of tin.展开更多
Zinc oxide (ZnO) thin films were deposited on sapphire (0001) substrates at room temperature by radiofrequency (RF) magnetron sputtering at oxygen gas contents of 0%, 25%, 50% and 75%, respectively. The influenc...Zinc oxide (ZnO) thin films were deposited on sapphire (0001) substrates at room temperature by radiofrequency (RF) magnetron sputtering at oxygen gas contents of 0%, 25%, 50% and 75%, respectively. The influence of oxygen gas content on the structural and optical properties of ZnO thin films was studied by a surface profile measuring system, X-ray diffraction analysis, atomic force microscopy, and UV spectro- photometry. It is found that the size of ZnO crystalline grains increases first and then decreases with the increase of oxygen gas content, and the maximum grain size locates at the 25% oxygen gas content. The crystalline quality and average optical transmittance (〉90%) in the visi- ble-light region of the ZnO film prepared at an oxygen gas content of 25% are better than those of ZnO films at the other contents. The obtained results can be attributed to the resputtefing by energetic oxygen anions in the growing process.展开更多
To increase the low-field magnetostriction of TbFe films, the influences of sputtering angles and annealing temperatures on its magnetic and magnetostrictive performances were systematically investigated. With the cha...To increase the low-field magnetostriction of TbFe films, the influences of sputtering angles and annealing temperatures on its magnetic and magnetostrictive performances were systematically investigated. With the change in sputtering angles from 90° to 15°, the in-plane magnetization of TbFe films, at 1600 kA·m-1 external field, is strongly increased. An enhancement in the in-plane magnetostrictive coefficient of the films at 40 kA·m-1 is also observed. A detection of magnetic domains by MFM (magnetic force microscopy) indicates that the easy magnetization direction shifts gradually from perpendicular to parallel to the film plane with decreasing sputtering angles. Annealing can enhance the magnetization and magnetostriction of the TbFe films. However, at too high annealing temperature, both the magnetization and magnetostriction of the TbFe films were suppressed to some extent.展开更多
Thick CrN coatings were deposited on Si (111) substrates by electron source assisted mid-frequency magnetron sputtering working at 40 kHz. The deposition rate, structure, and microhardness of the coatings were stron...Thick CrN coatings were deposited on Si (111) substrates by electron source assisted mid-frequency magnetron sputtering working at 40 kHz. The deposition rate, structure, and microhardness of the coatings were strongly influenced by the negative bias voltage (Vb). The deposition rate reached 8.96 μm/h at a Vb of -150 V. X-ray diffraction measurement revealed strong CrN (200) orientation for films prepared at low bias voltages. At a high bias voltage of Vb less than -25 V both CrN (200) and (111) were observed. Large and homogeneous grains were observed by both atomic force microscopy and scanning electron microscopy in samples prepared under optimal conditions. The samples exhibited a fibrous microstructure for a low bias voltage and a columnar structure for VD less than -150 V.展开更多
Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of develop...Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers (15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction, and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au (111) orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.展开更多
[FePt/Ag]n multilayers were deposited on glass substrates by RF magnetron sputtering and ex situ annealed at 550℃ for 30 min. The effects of inserted Ag layer thickness and the number of bilayer repetitions (n) on ...[FePt/Ag]n multilayers were deposited on glass substrates by RF magnetron sputtering and ex situ annealed at 550℃ for 30 min. The effects of inserted Ag layer thickness and the number of bilayer repetitions (n) on the structure and magnetic properties of the multilayers were investigated. It was found that the difference between in-plane and out-of-plane coercivities varied with an increase of inserted Ag layer thickness in the [FePt 2 nm/Ag x nm]10 multilayers. The ratio of out-of-plane coercivity to in-plane coercivity reached the maximum value with the Ag layer thickness of 5 nm, indicating that the Ag layer thickness plays an important role in obtaining perpendicular orientation. For the [FePt 2 nm/Ag 5 um]n multilayers, perpendicular orientation is also influenced by n. The maximum value of the ratio of out-of-plane coercivity to in-plane coercivity appeared when n was given as 8. It was found that the [FePt 2 nm/Ag 5 nm]8 had a high perpendicular coercivity of 520 kA/m and a low in-plane one of 88 kA/m, which shows a strong perpendicular anisotropy.展开更多
Cu films with thickness of 630-1300nm were deposited on glass substrates without heating by DC magnetron sputtering in pure Ar gas. Ar pressure was controlled to 0.5, 1.0 and 1.5Pa respectively. The target voltage was...Cu films with thickness of 630-1300nm were deposited on glass substrates without heating by DC magnetron sputtering in pure Ar gas. Ar pressure was controlled to 0.5, 1.0 and 1.5Pa respectively. The target voltage was fixed at 500V but the target current increased from 200 to 1150mA with Ar pressure increasing. X-ray diffraction, scanning electron microscopy and atomic force microscopy were used to observe the structural characterization of the films. The resistivity of the films was measured using four-point probe technique. At all the Ar pressures, the Cu films have mixture crystalline orientations of [111], [200] and [220] in the direction of the film growth. The film deposited at lower pressure shows more [111] orientation while that deposited at higher pressure has more [220] orientation. The amount of larger grains in the film prepared at 0.5Pa Ar pressure is slightly less than that prepared at 1.0Pa and 1.5Pa Ar pressures. The resistivities of the films prepared at three different Ar pressures represent few differences, about 3-4 times of that of bulk material. Besides the deposition rate increases with Ar pressure because of the increase in target current. The contribution of the bombardment of energetic reflected Argon atoms to these phenomena is discussed.展开更多
Low resistivity and highly transparent ITO conducting films for solar cell applications were fabricated at low temperature by r.f. magnetron sputtering. ITO films were deposited on glass and silicon substrate. Electri...Low resistivity and highly transparent ITO conducting films for solar cell applications were fabricated at low temperature by r.f. magnetron sputtering. ITO films were deposited on glass and silicon substrate. Electrical, optical, structural and morphological properties of the ITO films were investigated in terms of the preparation conditions. The annealing treatment has improved the properties of the ITO films at different degree. The maximum transmittance of the obtained ITO films in the visible range is over 92%, and the low resistivity for the ITO films are about 3.85×10-4 Ω·cm at 80 ℃, 80 W after annealing.展开更多
基金Funded by Shenzhen-Hong Kong Innovative Collaborative Research and Development Program (Nos.SGLH20181109 110802117, CityU 9240014)Innovation Project of Southwestern Institute of Physics (Nos.202001XWCXYD002, 202301XWCX003)CNNC Young Talent Program (No.2023JZYF-01)。
文摘Surface metallization of glass fiber(GF)/polyetheretherketone(PEEK)[GF/PEEK] is conducted by coating copper using electroplating and magnetron sputtering and the properties are determined by X-ray diffraction(XRD), scanning electron microscopy(SEM), and electron backscatter diffraction(EBSD).The coating bonding strength is assessed by pull-out tests and scribing in accordance with GB/T 9286-1998.The results show that the Cu coating with a thickness of 30 μm deposited on GF/PEEK by magnetron sputtering has lower roughness, finer grain size, higher crystallinity, as well as better macroscopic compressive stress,bonding strength, and electrical conductivity than the Cu coating deposited by electroplating.
基金the financial support from the National Key Research and Development Program of China(No.2017YFB0305500)the State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China.
文摘Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were investigated.As the sputtering power increases from 15 to 60 W,the Co thin films transition from an amorphous to a polycrystalline state,accompanied by an increase in the intercrystal pore width.Simultaneously,the resistivity decreases from 276 to 99μΩ·cm,coercivity increases from 162 to 293 Oe,and in-plane magnetic aniso-tropy disappears.As the sputtering pressure decreases from 1.6 to 0.2 Pa,grain size significantly increases,resistivity significantly de-creases,and the coercivity significantly increases(from 67 to 280 Oe),which can be attributed to the increase in defect width.Corres-pondingly,a quantitative model for the coercivity of Co thin films was formulated.The polycrystalline films sputtered under pressures of 0.2 and 0.4 Pa exhibit significant in-plane magnetic anisotropy,which is primarily attributable to increased microstress.
基金financial supports by National Natural Science Foundation of China(Nos.11975163 and 12175160)Nantong Basic Science Research-General Program(No.JC22022034)Natural Science Research Fund of Jiangsu College of Engineering and Technology(No.GYKY/2023/2)。
文摘This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide(ITO)target.The positive ion energies exhibit an upward trajectory with increasing RF power,attributed to heightened plasma potential and initial emergent energy.Simultaneously,the positive ion flux escalates owing to amplified sputtering rates and electron density.Conversely,negative ions exhibit broad ion energy distribution functions(IEDFs)characterized by multiple peaks.These patterns are clarified by a combination of radiofrequency oscillation of cathode voltage and plasma potential,alongside ion transport time.This elucidation finds validation in a one-dimensional model encompassing the initial ion energy.At higher RF power,negative ions surpassing 100 e V escalate in both flux and energy,posing a potential risk of sputtering damages to ITO layers.
基金supported by the National Key R&D Program of China(No.2019YFE0123900)the National Natural Sci-ence Foundation of China(Grant No.51974069)the Special Fund for Basic Scientific Research of Central Colleges(N2125035).
文摘The mechanical and frictional properties of ta-C coatings deposited on the substrate surface affect applications in the field of cutting tools and wear-resistant components.In this paper,the effect of bias parameters on the performance of ta-C coatings was investigated based on high power impulse magnetron sputtering(HiPIMS)technology.The results show that bias voltage has a significant effect on the deposition rate,structure,and wear resistance of the coating.In the range of bias voltage−50 V to−200 V,the ta-C coating performance was the best under bias voltage−150 V.The thickness reached 530.4 nm,the hardness value reached 35.996 GPa,and the bonding force in-creased to 14.2 N.The maximum sp3 bond content was 59.53% at this condition.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61974144, 62004127, and 12074263)Key-Area Research and Development Program of Guangdong Province (Grant Nos. 2020B010174003 and 2020B010169001)+2 种基金Guangdong Science Foundation for Distinguished Young Scholars (Grant No. 2022B1515020073)the Science and Technology Foundation of Shenzhen (Grant No. JSGG20191129114216474)the Open Project of State Key Laboratory of Functional Materials for Informatics。
文摘Al_(1-x)In_(x)N, a Ⅲ-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap energy varies from 0.7 eV to 6.2 eV, which shows great potential for application in photodetectors. Here, we report the fabrication and performance evaluation of integrated Al_(1-x)In_(x)N on a free-standing GaN substrate through direct radio-frequency magnetron sputtering.The optical properties of Al_(1-x)In_(x)N will be enhanced by the polarization effect of a heterostructure composed of Al_(1-x)In_(x)N and other Ⅲ-nitride materials. An Al_(1-x)In_(x)N/Ga N visible-light photodetector was prepared by semiconductor fabrication technologies such as lithography and metal deposition. The highest photoresponsivity achieved was 1.52 A·W^(-1)under 365 nm wavelength illumination and the photodetector was determined to have the composition Al0.75In0.25N/GaN.A rise time of 0.55 s was observed after transient analysis of the device. The prepared Al_(1-x)In_(x)N visible-light photodetector had a low dark current, high photoresponsivity and fast response speed. By promoting a low-cost, simple fabrication method,this study expands the application of ternary alloy Al_(1-x)In_(x)N visible-light photodetectors in optical communication.
基金Funded by the Young Top-notch Talent Cultivation Program of Hubei Provincethe Fundamental Research Funds for the Central Universities(WUT:2021IVA116 and WUT:2021CG015)。
文摘To achieve high microwave permeability in wide-band for the micron-thick magnetic films,[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer structure was proposed by co-sputtering Fe and FeNi to form the magnetic layers and Cr to form the interlayers.The multilayer structure contributes to the high permeability by reducing the coercivity and diminishing out-of-plane magnetization.The maximum imaginary permeability of[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer film reaches a large value of 800 at 0.52 GHz even though its overall thickness exceeds 1μm.Besides,the magnetic resonance frequency of the multilayer film can be modulated from 0.52 to 1.35 GHz by adjusting the sputtering power of Fe from 0 to 86 W,and its bandwidth for μ’’>200(Δf) is as large as 2.0 GHz.The desirable broad Δf of magnetic permeability,which can be well fitted by the Landau-Lifshitz-Gilbert equations,is due to dual magnetic resonances originated from double magnetic phases of Fe and FeNi that are of different saturation magnetization.The micron-thick multilayer films with high permeability in extended waveband are promising candidate for electromagnetic noise suppression application.
基金Project supported by the National Key Basic Research and Development Programme of China (Grant No 2001CB610504) and the National Natural Science Foundation of China (Grant Nos 60576039 and 10374060).Acknowledgments We thank Dr Wang Zhuo and Dr Yang ChangHong for their assistance in the experiment.
文摘Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency (RF) msgnetron sputtering at room temperature, The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power, The lowest resistivity achieved is 2.07 × 10^-3Ωcm at an RF power of 100W with a Hall mobility of 16cm^2V^-1s^-1 and a carrier concentration of 1.95 × 10^20 cm^-3. The films obtained are polycryetalline with a hexagonal structure and a preferred orientation along the c-axis, All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.
基金supported by a 2-Year Research Grant of Pusan National University,Korea
文摘The CrN and Cr-Al-Si-N films were deposited on Si wafer and SUS 304 substrates by a hybrid coating system with high power impulse magnetron sputtering (HIPIMS) and a DC pulse sputtering using Cr and AlSi targets under N2/Ar atmosphere.By varying the sputtering current of the AlSi target in the range of 0-2.5 A,both the Al and Si contents in the films increased gradually from 0 to 19.1% and 11.1% (mole fraction),respectively.The influences of the AlSi cathode DC pulse current on the microstructure,phase constituents,mechanical properties,and oxidation behaviors of the Cr-Al-Si-N films were investigated systematically.The results indicate that the as-deposited Cr-Al-Si-N films possess the typical nanocomposite structure,namely the face centered cubic (Cr,Al)N nano-crystallites are embedded in the amorphous Si3N4 matrix.With increasing the Al and Si contents,the hardness of the film first increases from 20.8 GPa for the CrN film to the peak value of 29.4 GPa for the Cr0.23Al0.14Si0.07 N film,and then decreases gradually.In the meanwhile,the Cr0.23Al0.14Si0.07N film also possesses excellent high-temperature oxidation resistance that is much better than that of the CrN film at 900 or 1000 °C.
文摘Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods. Unbalanced magnetron sputtering, by producing dense secondary plasma around the substrate, provides a high ion current density. The closed-field unbalanced magnetron sputtering system (CFUBMS) has been established as a versatile technique for high-rate deposition high-quality metal, alloy, and ceramic thin films. The'key factor in the CFUBMS system is the ability to transport high ion currents to the substrate, which can enhance the formation of full dense coatings at relatively low value homologous temperature. The investigation shows that the energy of ions incidenced at the substrate and the ratio of the flux of these ions to the flux of condensing atoms are the fundamental parameters in determining the structure and properties of films produced by ion-assisted deposition processes. Increasing ion bombardment during deposition combined with increasing mobility of the condensing atoms favors the formation of a dense microstructure and a smooth surface.
基金supported by the Dalian Foundation for Development of Science and Technology (No.2006A13GX029)
文摘TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-ray diffraction(XRD),atomic force microscopy(AFM) and ultraviolet spectrophotometer,respectively.The results indicated that working pressure was the key deposition parameter in?uencing the TiO2 film phase composition at room temperature,which directly affected its photocatalytic activity.With increasing working pressure,the target self-bias decreases monotonously.Therefore,low temperature TiO2 phase(anatase) could be deposited with high working pressure.The anatase TiO2 films deposited with 1.4 Pa working pressure displayed the highest photocatalytic activity by the decomposition of Methyl Orange solution,which the degradation rate reached the maximum(35%) after irradiation by ultraviolet light for 1 h.
基金[This work was financially supported by the National Natural Science Foundation of China (No.50402024)Natural Science Foundation of Gansu Province (No.ZS 041-A25-033).
文摘V2O5 films were prepared on silicon wafers by DC magnetron sputtering and post-annealing under various conditions. The influence of depositing and post-annealing temperatures on microstructure of V2O5 films was studied by XRD and Raman scattering measurements. The results reveal that sputtered V2O5 films show preferred growth orientation along (001) planes and the c-axis is perpendicular to the silicon substrate surface. It is interesting to find that both the V2O5 film deposited at temperature of 511 ℃ and the one annealed at 500 ℃ exhibit desirable layer-type structure of orthorhombic symmetry. Such layer-typed V2O5 films are promising candidates for cathodes of rechargeable lithium or magnesium thin-film batteries.
基金the National Nature Science Foundation of China (Nos. 50771046 and 20373016) the Natural Science Foundation of Guangdong Province (No. 05200534)the Key Projects of Guangdong Province and Guangzhou City, China (Nos. 2006A10704003 and 2006Z3-D2031)
文摘A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of-50 nm in thickness on it were fabricated by magnetron sputtering. The surface morphology, composition, surface distributions of alloy elements, and lithium intercalation/de-intercalation behaviors of the fabricated films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectrometry (ICP), cyclic voltammetry (CV), and galvanostatic charge/discharge (GC) measurements. It is found that the lithium intercalation/de-intercalation behavior of the Sn film can be significantly improved by its composite with graphite. With cycling, the discharge capacity of the Sn film without composite changes from 570 mAh/g of the 2nd cycle to 270 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 90% and 95%. Nevertheless, the discharge capacity of the composite Sn/C film changes from 575 mAh/g of the 2nd cycle to 515 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 95% and 100%. The performance improvement of tin by its composite with graphite is ascribed to the retardation of the bulk tin cracking from volume change during lithium intercalation and de-intercalation, which leads to the pulverization of tin.
基金supported by the National Natural Science Foundation of China (Nos. 60876055 and11074063)the Natural Science foundation of Hebei Province,China (Nos. E2008000620 and E2009000207)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20091301110002)the Key Basic Research Program of Hebei Provincial Applied Basic Research Plan (No. 10963525D)
文摘Zinc oxide (ZnO) thin films were deposited on sapphire (0001) substrates at room temperature by radiofrequency (RF) magnetron sputtering at oxygen gas contents of 0%, 25%, 50% and 75%, respectively. The influence of oxygen gas content on the structural and optical properties of ZnO thin films was studied by a surface profile measuring system, X-ray diffraction analysis, atomic force microscopy, and UV spectro- photometry. It is found that the size of ZnO crystalline grains increases first and then decreases with the increase of oxygen gas content, and the maximum grain size locates at the 25% oxygen gas content. The crystalline quality and average optical transmittance (〉90%) in the visi- ble-light region of the ZnO film prepared at an oxygen gas content of 25% are better than those of ZnO films at the other contents. The obtained results can be attributed to the resputtefing by energetic oxygen anions in the growing process.
基金We are grateful to the National Natural Science Foundation of China(Grant No.50271014)for the financial support of this work.
文摘To increase the low-field magnetostriction of TbFe films, the influences of sputtering angles and annealing temperatures on its magnetic and magnetostrictive performances were systematically investigated. With the change in sputtering angles from 90° to 15°, the in-plane magnetization of TbFe films, at 1600 kA·m-1 external field, is strongly increased. An enhancement in the in-plane magnetostrictive coefficient of the films at 40 kA·m-1 is also observed. A detection of magnetic domains by MFM (magnetic force microscopy) indicates that the easy magnetization direction shifts gradually from perpendicular to parallel to the film plane with decreasing sputtering angles. Annealing can enhance the magnetization and magnetostriction of the TbFe films. However, at too high annealing temperature, both the magnetization and magnetostriction of the TbFe films were suppressed to some extent.
基金supported by National Natural Science Foundation of China(Nos.10435060,10675095)
文摘Thick CrN coatings were deposited on Si (111) substrates by electron source assisted mid-frequency magnetron sputtering working at 40 kHz. The deposition rate, structure, and microhardness of the coatings were strongly influenced by the negative bias voltage (Vb). The deposition rate reached 8.96 μm/h at a Vb of -150 V. X-ray diffraction measurement revealed strong CrN (200) orientation for films prepared at low bias voltages. At a high bias voltage of Vb less than -25 V both CrN (200) and (111) were observed. Large and homogeneous grains were observed by both atomic force microscopy and scanning electron microscopy in samples prepared under optimal conditions. The samples exhibited a fibrous microstructure for a low bias voltage and a columnar structure for VD less than -150 V.
基金supported by the National Key R&D Program of China(Nos.2016YFA0401304 and 2017YFA0403302)the National Natural Science Foundation of China(NSFC)(Nos.61621001,11505129,and U1732268)
文摘Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers (15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction, and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au (111) orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.
基金This work is financially supported by the National Natural Science Foundation of China (No. 10574085) Natural Science Foundation ofShanxi Province, China (No. 20041032).
文摘[FePt/Ag]n multilayers were deposited on glass substrates by RF magnetron sputtering and ex situ annealed at 550℃ for 30 min. The effects of inserted Ag layer thickness and the number of bilayer repetitions (n) on the structure and magnetic properties of the multilayers were investigated. It was found that the difference between in-plane and out-of-plane coercivities varied with an increase of inserted Ag layer thickness in the [FePt 2 nm/Ag x nm]10 multilayers. The ratio of out-of-plane coercivity to in-plane coercivity reached the maximum value with the Ag layer thickness of 5 nm, indicating that the Ag layer thickness plays an important role in obtaining perpendicular orientation. For the [FePt 2 nm/Ag 5 um]n multilayers, perpendicular orientation is also influenced by n. The maximum value of the ratio of out-of-plane coercivity to in-plane coercivity appeared when n was given as 8. It was found that the [FePt 2 nm/Ag 5 nm]8 had a high perpendicular coercivity of 520 kA/m and a low in-plane one of 88 kA/m, which shows a strong perpendicular anisotropy.
基金The authors would like to thank Prof. Y.B. Wang and Mr. S. Liang of the Department of Material Physics for supporting AFM observations. The authors also would like to thank Ms. J.P. He of the State Key Laboratory for Advanced Metals and Materials for sup
文摘Cu films with thickness of 630-1300nm were deposited on glass substrates without heating by DC magnetron sputtering in pure Ar gas. Ar pressure was controlled to 0.5, 1.0 and 1.5Pa respectively. The target voltage was fixed at 500V but the target current increased from 200 to 1150mA with Ar pressure increasing. X-ray diffraction, scanning electron microscopy and atomic force microscopy were used to observe the structural characterization of the films. The resistivity of the films was measured using four-point probe technique. At all the Ar pressures, the Cu films have mixture crystalline orientations of [111], [200] and [220] in the direction of the film growth. The film deposited at lower pressure shows more [111] orientation while that deposited at higher pressure has more [220] orientation. The amount of larger grains in the film prepared at 0.5Pa Ar pressure is slightly less than that prepared at 1.0Pa and 1.5Pa Ar pressures. The resistivities of the films prepared at three different Ar pressures represent few differences, about 3-4 times of that of bulk material. Besides the deposition rate increases with Ar pressure because of the increase in target current. The contribution of the bombardment of energetic reflected Argon atoms to these phenomena is discussed.
基金This project was financially supported by the Natural Science Foundation of Hebei Province, China. (No. F2005000073).
文摘Low resistivity and highly transparent ITO conducting films for solar cell applications were fabricated at low temperature by r.f. magnetron sputtering. ITO films were deposited on glass and silicon substrate. Electrical, optical, structural and morphological properties of the ITO films were investigated in terms of the preparation conditions. The annealing treatment has improved the properties of the ITO films at different degree. The maximum transmittance of the obtained ITO films in the visible range is over 92%, and the low resistivity for the ITO films are about 3.85×10-4 Ω·cm at 80 ℃, 80 W after annealing.