Microstructure and Nonlinear Optical Properties of Very Small Size GaAs Nanogranulae Embedded in SiO_2 Matrix by Magnetron Co-Sputtering

Microstructure of GaAs/SiO 2 nanogranular thin films fabricated by radio frequency magnetron co sputtering technique and postannealing are investigated via atomic force microscope,X ray diffraction,and Rutherford backscattering spectroscopy.The results show that GaAs nanocrystals with average diameters from 1 5nm to 3 2nm (depending on the annealing temperature) are uniformly dispersed in the SiO 2 matrices.GaAs and SiO 2 are found in normal stoichiometry in the films.The nonlinear optical refraction and nonlinear optical absorption are studied by Z scan technique using a single Gaussian beam of pulse laser.The third order nonlinear optical refractive index and nonlinear absorption coefficient are enhanced due to the quantum confinement effects and estimated to be 4×10 -12 m 2/W and 2×10 -5 m/W respectively in nonresonant condition,while 2×10 -11 m 2/W and -1×10 -4 m/W respectively in quasi resonant condition.

Intermetallic Pt_2Si:magnetron-sputtering preparation and electrocatalysis toward ethanol oxidation

Although most transition metals have been tested as the promoter to Pt for electrocatalysis toward fuel cell reactions,semi-conductor elements,such as Si,have hitherto not been examined.Here we report a simple synthesis of intermetallic Pt2Si electrode using magnetron sputtering and the electrocatalysis toward ethanol oxidation reaction（EOR）.In comparison to Pt,the intermetallic Pt2Si surface turns out to be much more active in catalyzing the EOR：the onset potential shifts negatively by 150 mV,and the current density at 0.6 V increases by a magnitude of one order.Such an enormous enhancement in EOR catalysis is ascribed to the promotion effects of Si,which can not only provide active surface oxygenated species to accelerate the removal of COads,but also strongly alter the electronic property of Pt,as clearly indicated by the core-level shift in XPS spectrum.

The electrical,optical properties of AlSb polycrystalline thin films deposited by magnetron co-sputtering without annealing

In order to fabricate A1Sb polycrystalline thin films without post annealing, this paper studies a technology of magnetron co-sputtering onto intentionally heated substrate. It compares the structural characteristics and electrical properties of A1Sb films which are deposited at different substrate temperatures. It finds that the films prepared at a substrate temperature of 450 ℃ exhibit an enhanced grain growth with an average grain size of 21 nm and the lattice constant is 0.61562 nm that goes well with unstained lattice constant （0.61355 nm）. The ln（σdark） -1/T curves show that the conductivity activation energy is about 0.38 eV when the film is deposited at 450 ℃ without an annealing. The transmittance and reflectance spectra show that the film deposited at 450 ℃ has an optical band gap of 1.6 eV. These results indicate that we have prepared A1Sb polycrystalline films which do not need a post annealing.

Preparation,structure and ferromagnetic properties of the nanocrystalline Ti_(1-x)Mn_xO_2 thin films grown by radio frequency magnetron co-sputtering

This paper reported that the Mn-doped TiO2 films were prepared by radio frequency （RF） magnetron cosputtering. X-ray diffraction measurements indicate that the samples are easy to form the futile structure, and the sizes of the crystal grains grow big and big as the Mn concentration increases. X-ray photoemlssion spectroscopy measurements and high resolution transmission electron microscope photographs confirm that the manganese ions have been effectively doped into the TiO2 crystal when the Mn concentration is lower than 21%. The magnetic property measurements show that the Ti1-xMnxO2 （x = 0.21） films are ferromagnetic at room temperature, and the saturation magnetization, coercivity, and saturation field are 16.0 emu/cm^3, 167.5 × 80 A/m and 3740 × 80 A/m at room temperature, respectively. The room-temperature ferromagnetism of the films can be attributed to the new futile Ti1-xMnxO2 structure formed by the substitution of Mn^4＋ for Ti^4＋ into the TiO2 crystal .lattice, and could be explained by O vacancy （Vo）-enhanced ferromagnetism model.

Effect of substrate temperature and oxygen plasma treatment on the properties of magnetron-sputtered CdS for solar cell applications

Cadmium sulfide(CdS)is an n-type semiconductor with excellent electrical conductivity that is widely used as an electron transport material(ETM)in solar cells.At present,numerous methods for preparing CdS thin films have emerged,among which magnetron sputtering(MS)is one of the most commonly used vacuum techniques.For this type of technique,the substrate temperature is one of the key deposition parameters that affects the interfacial properties between the target film and substrate,determining the specific growth habits of the films.Herein,the effect of substrate temperature on the microstructure and electrical properties of magnetron-sputtered CdS(MS-CdS)films was studied and applied for the first time in hydrothermally deposited antimony selenosulfide(Sb_(2)(S,Se)_(3))solar cells.Adjusting the substrate temperature not only results in the design of the flat and dense film with enhanced crystallinity but also leads to the formation of an energy level arrangement with a Sb_(2)(S,Se)_(3)layer that is more favorable for electron transfer.In addition,we developed an oxygen plasma treatment for CdS,reducing the parasitic absorption of the device and resulting in an increase in the short-circuit current density of the solar cell.This study demonstrates the feasibility of MS-CdS in the fabrication of hydrothermal Sb_(2)(S,Se)_(3)solar cells and provides interface optimization strategies to improve device performance.

Structural,optical,and electrical properties of Cu-doped ZrO_2 films prepared by magnetron co-sputtering

Copper （Cu）-doped ZrO2 （CZO） films with different Cu content （0 at.%- 8.07 at.%） are successfully deposited on Si （100） substrates by direct current （DC） and radio frequency （RF） magnetron co-sputtering. The influences of Cu content on structural, morphological, optical and electrical properties of CZO films are discussed in detail. The CZO films exhibit ZrO2 monocline （1^-11） preferred orientation, which indicates that Cu atoms are doped in ZrO2 host lattice. The crystallite size estimated form x-ray diffraction （XRD） increases by Cu doping, which accords with the result observed from the scanning electron microscope （SEM）. The electrical resistivity decreases from 2.63 Ω·cm to 1.48 Ω·cm with Cu doping content increasing, which indicates that the conductivity of CZO film is improved. However, the visible light transmittances decrease slightly by Cu doping and the optical band gap values decrease from 4.64 eV to 4.48 eV for CZO fihns.

Effects of Titanium Sputtering Current on Structure and Morphology of TiZrN Films Prepared by Reactive DC Magnetron Co-Sputtering

TiZrN films were deposited on unheated Si (100) substrates by reactive dc magnetron co-sputtering. Titanium and zirconium metals were used as sputtering targets. Ar and N2 gas were used as sputtering gas and reactive gas, with the flow rates of 8 and 4 sccm, respectively. The Zr sputtering current was fixed at 0.6 A and Ti sputtering current varied from 0.6 to 1.2 A. The deposition time for all the deposited films was 60 min. The effects of Ti sputtering current on the structure and morphology of the films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). It was found that all the prepared films were (Ti,Zr)N solid solution. Furthermore, the lattice parameter was found to decrease whereas the crystallite size, RMS roughness and film thickness increased with increasing Ti sputtering current. As a result, the crystallinity of the films increased what is in agreement with XRD results.

Effects of Vanadium Content on Structure and Chemical State of TiVN Films Prepared by Reactive DC Magnetron Co-Sputtering

TiVN films were deposited on Si(100) wafers without external heating and biasing by reactive dc magnetron co-sputtering. Titanium and vanadium metals were used as sputtering targets. Ar and N2 gases were used as sputtering gas and reactive gas, respectively. The flow rates of Ar and N2 were 8 and 4 sccm, respectively. The Ti sputtering current (ITi) was kept constant at 0.6 Aand V sputtering current (IV) was varied from 0.4 to1.0 A. The deposition time for all the deposited films was 30 min. The effects of V sputtering current on the structure, surface and cross-sectional morphologies, and chemical composition and chemical state of the films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS), respectively. It was found that all the prepared film formed (Ti,V)N solid solution. The lattice parameter was found to decrease while crystallite size, RMS roughness and film thickness increased with increasing V sputtering current. High resolution XPS spectra of the Ti 2p, V 2p and N 1s revealed that the fraction of Ti-N and V-N bonds increased as the V sputtering current increased. However, the V-N bond was observed only at a high V sputtering current.

Continuous compositional spread investigation of SiC-based thin films prepared by MW-ECR plasma enhanced magnetron co-sputtering

A kind of combinatorial material methodology,also known as continuous compositional spread method,was employed to investigate the relationship between the optical band gap and composition of SiC thin films.A wide range of SixCy thin films with different carbon contents have been successfully deposited in a single deposition by carefully arranging the sample position on the substrate holder.The films were characterized by surface profiler,x-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy,fourier transform infrared spectroscopy and Raman spectroscopy.The carbon content y increases linearly from 0.28 to 0.72 while the sample position changed from 85 to 175 mm,the optical band gap changed between 1.27 and 1.99 eV,the maximum value corresponded to the stoichiometric SiC sample at the position of 130 mm,which has the highest Si?C bond density of 11.7×10^22 cm^-3.The C poor and C rich SixCy samples with y value less and larger than 0.5 were obtained while samples deviated from the position 130 mm,the optical band gap decreased with the Si?C bond density.

Origin of Initial Current Peak in High Power Impulse Magnetron Sputtering and Verification by Non-Sputtering Discharge

A non-sputtering discharge is utilized to verify the effect of replacement of gas ions by metallic ions and consequent decrease in the secondary electron emission coefficient in the discharge current curves in high-power impulse magnetron sputtering （HiPIMS）. In the non-sputtering discharge involving hydrogen, replacement of ions is avoided while the rarefaction still contributes. The initial peak and ensuing decay disappear and all the discharge current curves show a similar feature as the HiPIMS discharge of materials with low sputtering yields such as carbon. The results demonstrate the key effect of ion replacement during sputtering.

Dielectric Properties of ZrTiO4 Thin Films Prepared by Reactive DC Magnetron Co-sputtering

ZrTiO4 is a small ceramic constituent material which has very good thermal and electrical properties. ZrTiO4 thin films were deposited by reactive dc magnetron co-sputtering method. The crystal structure, surface morphology, thickness and dielectric properties were characterized by XRD （X-ray diffraction）, AFM （atomic force microscopy）, FE-SEM （field emission scanning electron microscope）, and precision impedance analyzer respectively. These films were crystallization of the orthorhombic phase （111） of ZrTiOa. The microstructure of well-crystallized ZrTiO4 thin films had the surface morphology was smooth with 1.695 nmrms roughness. The high dielectric constant width decreases from 129.2 to 110.6 when sputtering current increases which are higher more than that had researched because of higher energy but impedance; ｜Z｜ increases from 1.97 to 2.47 kΩ. These results are consistent with the RMS roughness results, which are the RMS roughness decrease with increasing sputtering current.

Structural,Morphological and Electrical Properties of In-Doped Zinc Oxide Nanostructure Thin Films Grown on p-Type Gallium Nitride by Simultaneous Radio-Frequency Direct-Current Magnetron Co-Sputtering

Zinc oxide （ZnO） is one of the most promising and frequently used semiconductor materials. In-doped nanos- tructure ZnO thin films are grown on p-type gallium nitride substrates by employing the simultaneous rf and dc magnetron co-sputtering technique. The effect of In-doping on structural, morphological and electrical properties is studied. The different dopant concentrations are accomplished by varying the direct current power of the In target while keeping the fixed radio frequency power of the ZnO target through the co-sputtering deposition technique by using argon as the sputtering gas at ambient temperature. The structural analysis confirms that all the grown thin films preferentially orientate along the c-axis with the wurtzite hexagonal crystal structure without having any kind of In oxide phases. The presenting Zn, 0 and In elements＇ chemical compositions are identified with EDX mapping analysis of the deposited thin films and the calculated M ratio has been found to decrease with the increasing In power. The surface topographies of the grown thin films are examined with the atomic force microscope technique. The obtained results reveal that the grown film roughness increases with the In power. The Hall measurements ascertain that all the grown films have n-type conductivity and also the other electrical parameters such as resistivity,mobility and carrier concentration are analyzed.

Surface Metallization of Glass Fiber(GF)/Polyetheretherketone(PEEK) Composite with Cu Coatings Deposited by Magnetron Sputtering and Electroplating

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.

High Permeability in Broadband of Co-sputtered [Fe-Fe_(20)Ni_(80)/Cr]_(n) Multilayer Films

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.

Structural and magnetic properties of micropolycrystalline cobalt thin films fabricated by direct current magnetron sputtering

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.

Preparation and Properties of Cu-Containing High-entropy Alloy Nitride Films by Magnetron Sputtering on Titanium Alloy

Magnetron sputtering deposition with regulated Cu target power was used for depositing Cu-containing high-entropy alloy nitride(Cu-(HEA)N)films on TC4 titanium alloy substrates.The microscopic morphologies,surface compositions,and thicknesses of the films were characterized using SEM+EDS;the anti-corrosion,wear resistance and antibacterial properties of the films in simulated seawater were investigated.The experimental results show that all four Cu-(HEA)N films are uniformly dense and contained nanoparticles.The film with Cu doping come into contact with oxygen in the air to form cuprous oxide.The corrosion resistance of the(HEA)N film without Cu doping on titanium alloy is better than the films with Cu doping.The Cu-(HEA)N film with Cu target power of 16 W shows the best wear resistance and antibacterial performance,which is attributed to the fact that Cu can reduce the coefficient of friction and exacerbate corrosion,and the formation of cuprous oxide has antibacterial properties.The findings of this study provide insights for engineering applications of TC4 in the marine field.

Exploring negative ion behaviors and their influence on properties of DC magnetron sputtered ITO films under varied power and pressure conditions

We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of discharge power and discharge pressure on the ion flux and energy distribution function of incidence on the substrate surface,with special attention to the production of high-energy negative oxygen ions,and elucidate the mechanism behind its production.At the same time,the structure and properties of ITO films are systematically characterized to understand the potential effects of high energy oxygen ions on the growth of ITO films.Combining with the kinetic property analysis of sputtering damage mechanism of transparent conductive oxide(TCO)thin films,this study provides valuable physical understanding of optimization of TCO thin film deposition process.

Effects of power on ion behaviors in radio-frequency magnetron sputtering of indium tin oxide(ITO)

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.

Study of bias voltage effect on the performance of ta-C coating prepared by high power impulse magnetron sputtering

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.

Synthesis of One-Dimensional ZnO Na norods by Oxidating Zinc Films Deposited with Magnetron Sputtering

One-dimensional ZnO nanorods are synthesized by ox idating thin metal zinc films deposited on Si(111) substrates with radio frequen cy magnetron sputtering.The crystal structure,surface morphology,and optical pro perties of nanorods are investigated.X-ray diffraction(XRD) pattern,scanning el ectron microscopy(SEM),and transmission electron microscopy(TEM) analyses show t hat the synthesized single-crystal ZnO nanorods develop like hairpins along dif ferent radials,with a hexagonal wurtzite structure.The diameters of nanorods ran ge between 30 and 60nm and lengths up to micrometers.Photoluminescence(PL) analy sis shows that,under 280nm light excitation,a strong and sharp near band-edge U V light emission band at 372nm and a relatively weak green deep-level light emi ssion band at 516nm are observed from the ZnO nanorods,which indicates excellent crystallization and optical quality of the fabricated ZnO nanorods.