Spinel NiZn ferrite thin films were prepared on glass substrates by spray plating method. Adding cetyltrimethylammoniumchloride （CTAC）, adsorptive energy of substrate surface increased, and smooth surface and unifor...Spinel NiZn ferrite thin films were prepared on glass substrates by spray plating method. Adding cetyltrimethylammoniumchloride （CTAC）, adsorptive energy of substrate surface increased, and smooth surface and uniform columnar film structures were observed. The optimum reaction temperature up to 85℃ and pH up to 7.5 were obtained. As the solution pH value increases from 6.5 to 7.5, the film saturation magnetization increases to 36.1 and the imaginary part μ″ up to 53.2 for NiZn ferrite film at 500 MHz were achieved, and higher magnetic resonance at 508 MHz was observed. As the ferrite plate thickness is 50 μm, the attenuating characteristics for reflection loss ≤-0.8 dB can be obtained in the wide frequency ranging from 0.5 to 2.7 GHz. Theμ″ of thin film has values higher than 20 at the frequencies between 0.5 and 2 GHz, and the thin film can be applied as shielding material in GHz range.展开更多
NiZn ferrite thin fihns were performed on glass substrates of 85 ℃ by spin spray plating method. X-ray diffraction patterns of the films show that the samples have a cubic spinel structure with no extra lines corresp...NiZn ferrite thin fihns were performed on glass substrates of 85 ℃ by spin spray plating method. X-ray diffraction patterns of the films show that the samples have a cubic spinel structure with no extra lines corresponding to any other phases between 75 ℃ and 85 ℃. As the pH value of oxidizing solution increases to 8.3, the saturation magnetization increases to 3.13 × 10^5 A/m and resistivity to 127 m Ω ·cm. Film deposited at pH 7.8 has a smooth surface and definite columnar structure. The large wavy flakes were observed at pH 8.3. The high real part of complex permeability μ′ up to 36.1 and the imaginary part μ″ up to 53.2 were observed at 0.5 GHz by short microstrip line perturbation method. The μ″ of thin film has values higher than 20 at the frequencies between 0.5 GHz and 2 GHz, the film is a promising anti-noise material for high frequency applications,展开更多
Ni0.7Zn0.3Fe2O4/Co0.8Fe2.2O4（NZFO/CFO） multilayer films are fabricated on Si（lO0） substrates by the chemical solution deposition method. The mierostructure and magnetic properties are systematically investigated. ...Ni0.7Zn0.3Fe2O4/Co0.8Fe2.2O4（NZFO/CFO） multilayer films are fabricated on Si（lO0） substrates by the chemical solution deposition method. The mierostructure and magnetic properties are systematically investigated. The results of field-emission scanning electronic microscopy show that the grain size of the NZFO/CFO multilayer film is quite uniform and the thickness is about 30Ohm. The remanence enhancement effect of the NZFO/CFO multilayer film can be mainly attributed to the exchange coupling interaction between NZFO and CFO ferrite films, which is in favor of the design and fabrication of modern electronic devices.展开更多
A new nanometer-scale ferrite thin film with excellent high-frequency characteristics has been developed by the spray-spin-heating-coating method. The effects of the ion synthesis mechanism, chemical stoichiometry, fa...A new nanometer-scale ferrite thin film with excellent high-frequency characteristics has been developed by the spray-spin-heating-coating method. The effects of the ion synthesis mechanism, chemical stoichiometry, fabrication method, and doping content on the magnetic properties and microstructure of the thin films have been analyzed. The films formed between 75℃ and 90℃ by spray-spin-heating-coating methods was discovered with fine grain size of about 21 nm, high saturation magnetization (4πMs) of about 6.5 kGs, coercivity of about 9.8 Oe, as well as initial permeability of about 14.0. These films can be widely used in radio-frequency integrated circuit devices.展开更多
Cu- and Co-substituted NiZn ferrite thin films, Ni0.4-xZn0.6CuxFe2O4 and Ni0.5Zn0.5CoxFe2-xO4 （0≤x≤0.2）, are synthesized by sol-gel process. The crystallographic and magnetic properties of Cu- and Co-substituted N...Cu- and Co-substituted NiZn ferrite thin films, Ni0.4-xZn0.6CuxFe2O4 and Ni0.5Zn0.5CoxFe2-xO4 （0≤x≤0.2）, are synthesized by sol-gel process. The crystallographic and magnetic properties of Cu- and Co-substituted NiZn ferrite thin films have been investigated. The lattice parameter decreases with Cu substitution and increases with Co substitution. The saturation magnetization decreases and the coereivity increases with the increase of Cu substitution. Moreover, the saturation magnetization gradually increases with the increase of Co substitution when x≤0.10, but decreases when x〉0.10. Meanwhile, the coereivity initially decreases with the increase of Co substitution when x≤0.10, but increases when x〉0.10.展开更多
BiFeO_(3)(BFO),Mn-doped-BFO(BFMO),Ti-doped-BFO(BFTO),and(Mn,Ti)-codoped-BFO(BFMTO)thin films are fabricated on the Pt/TiO_(2)/SiO_(2)/Si substrates via a sol–gel method combined with spin-coating and the subsequent l...BiFeO_(3)(BFO),Mn-doped-BFO(BFMO),Ti-doped-BFO(BFTO),and(Mn,Ti)-codoped-BFO(BFMTO)thin films are fabricated on the Pt/TiO_(2)/SiO_(2)/Si substrates via a sol–gel method combined with spin-coating and the subsequent layer-by-layer annealing technique.Compared with BFO film,the BFMTO film exhibits the lowest leakage current density(-10^(-4) A/cm^(2)@290 kV/cm).Notably,the polarization–electric field(P–E)loop of BFMTO film exhibits a positive displacement along the x-axis due to the existence of internal bias electric field,which is in agreement with the results of the PFM phase and amplitude curves.Especially,a very prominent inverse piezoelectric constant of d_(33)-160 pm/V was obtained,which overcomes other related thin films.The internal bias electric field of BFMTO film can be caused by the different work functions of the thin film and the bottom electrode,accumulation of oxygen vacancies and the formation of defect dipoles.Besides,the internal bias electric field of BFMTO film has a good stability at the same electric field after experiencing the test cycle from low electric field to high electric field(400–1900 kV/cm).These results indicate that self-polarized BFMTO film can be integrated to devices without additional polarization process,and have a wide range of application in microelectromechanical systems.展开更多
There are few relevant researches on coils by tempering,and the variations of microstructure and properties of steel coil during the tempering process also remain unclear.By using thermo-mechanical control process（T...There are few relevant researches on coils by tempering,and the variations of microstructure and properties of steel coil during the tempering process also remain unclear.By using thermo-mechanical control process（TMCP）technology,Mn-Ti typical HSLA steel coils with yield strength of 920 MPa are produced on the 2250 hot rolling production line.Then,the samples are taken from the coils and tempered at the temperatures of 220℃,350℃,and 620℃respectively.After tempering the strength,ductility and toughness of samples are tested,and meanwhile microstructures are investigated.Precipitates initially emerge inside the ferrite laths and the density of the dislocation drops.Then,the lath-shaped ferrites begin to gather,and the retained austenite films start to decompose.Finally,the retained austenite films are completely decomposed into coarse and short rod-shape precipitates composed of C and Ti compounds.The yield strength increases with increasing tempering temperature due to the pinning effect of the precipitates,and the dislocation density decreases.The yield strength is highest when the steel is tempered at 220℃because of pinning of the precipitates to dislocations.The total elongation increases in all samples because of the development of ferrites during tempering.The tensile strength and impact absorbed energy decline because the effect of impeding crack propagation weakens as the retained austenite films completely decompose and the precipitates coarsen.This paper clarifies the influence of different tempering temperatures on phase transformation characteristics and process of Mn-Ti typical multiphase steels,as well as its resulting performance variation rules.展开更多
We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for ...We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for the inforcom technologies. GHz magnetic properties of the soft magnetic thin films with in-plane anisotropy were investigated. It is found that several hundreds of permeability at the GHz frequency was achieved for Col00_xZrx and Co90Nbl0 metallic thin films because of their high satu- ration magnetization, and an adjustable resonance frequency from 1.3 to 4.9 GHz was obtained. Compared with the metallic thin films, the weaker saturation magnetization of Ni-Zn ferrite thin films results in several tens of permeability at the GHz frequency, but the larger resistivity of the ferrite prepared in situ without any heating treatments has lower energy loss. In order to obtain materials with large permeability and low energy loss in the GHz range, the [CoFe-NiZn ferrite] composite granular thin films were investigated, where the advantage of higher saturation magnetization for the metallic alloy and the high resis- tivity as well as high saturation magnetization for the ferrite results in a good GHz magnetic performance.展开更多
文摘Spinel NiZn ferrite thin films were prepared on glass substrates by spray plating method. Adding cetyltrimethylammoniumchloride （CTAC）, adsorptive energy of substrate surface increased, and smooth surface and uniform columnar film structures were observed. The optimum reaction temperature up to 85℃ and pH up to 7.5 were obtained. As the solution pH value increases from 6.5 to 7.5, the film saturation magnetization increases to 36.1 and the imaginary part μ″ up to 53.2 for NiZn ferrite film at 500 MHz were achieved, and higher magnetic resonance at 508 MHz was observed. As the ferrite plate thickness is 50 μm, the attenuating characteristics for reflection loss ≤-0.8 dB can be obtained in the wide frequency ranging from 0.5 to 2.7 GHz. Theμ″ of thin film has values higher than 20 at the frequencies between 0.5 and 2 GHz, and the thin film can be applied as shielding material in GHz range.
基金the Advanced Research Project of the General Armament De-partment of China
文摘NiZn ferrite thin fihns were performed on glass substrates of 85 ℃ by spin spray plating method. X-ray diffraction patterns of the films show that the samples have a cubic spinel structure with no extra lines corresponding to any other phases between 75 ℃ and 85 ℃. As the pH value of oxidizing solution increases to 8.3, the saturation magnetization increases to 3.13 × 10^5 A/m and resistivity to 127 m Ω ·cm. Film deposited at pH 7.8 has a smooth surface and definite columnar structure. The large wavy flakes were observed at pH 8.3. The high real part of complex permeability μ′ up to 36.1 and the imaginary part μ″ up to 53.2 were observed at 0.5 GHz by short microstrip line perturbation method. The μ″ of thin film has values higher than 20 at the frequencies between 0.5 GHz and 2 GHz, the film is a promising anti-noise material for high frequency applications,
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274314,11374304,51102072,21201052 and U1632161the Natural Science Major Foundation of Anhui Provincial Higher Education Institutions under Grant No KJ2012ZD14+2 种基金the Natural Science Foundation of Anhui Province under Grant No 1508085MA18the Postdoctoral Science Foundation of China under Grant No 2013M541848the Foundation for University Key Teachers from Hefei Normal University under Grant No2014136JKC08
文摘Ni0.7Zn0.3Fe2O4/Co0.8Fe2.2O4（NZFO/CFO） multilayer films are fabricated on Si（lO0） substrates by the chemical solution deposition method. The mierostructure and magnetic properties are systematically investigated. The results of field-emission scanning electronic microscopy show that the grain size of the NZFO/CFO multilayer film is quite uniform and the thickness is about 30Ohm. The remanence enhancement effect of the NZFO/CFO multilayer film can be mainly attributed to the exchange coupling interaction between NZFO and CFO ferrite films, which is in favor of the design and fabrication of modern electronic devices.
基金supported by the National Natural Science Foundation of China under grant No.69671021.
文摘A new nanometer-scale ferrite thin film with excellent high-frequency characteristics has been developed by the spray-spin-heating-coating method. The effects of the ion synthesis mechanism, chemical stoichiometry, fabrication method, and doping content on the magnetic properties and microstructure of the thin films have been analyzed. The films formed between 75℃ and 90℃ by spray-spin-heating-coating methods was discovered with fine grain size of about 21 nm, high saturation magnetization (4πMs) of about 6.5 kGs, coercivity of about 9.8 Oe, as well as initial permeability of about 14.0. These films can be widely used in radio-frequency integrated circuit devices.
基金supported by the Scientific Research Foundation of Chengdu University of Information Technology under Grant No.KYTZ201022
文摘Cu- and Co-substituted NiZn ferrite thin films, Ni0.4-xZn0.6CuxFe2O4 and Ni0.5Zn0.5CoxFe2-xO4 （0≤x≤0.2）, are synthesized by sol-gel process. The crystallographic and magnetic properties of Cu- and Co-substituted NiZn ferrite thin films have been investigated. The lattice parameter decreases with Cu substitution and increases with Co substitution. The saturation magnetization decreases and the coereivity increases with the increase of Cu substitution. Moreover, the saturation magnetization gradually increases with the increase of Co substitution when x≤0.10, but decreases when x〉0.10. Meanwhile, the coereivity initially decreases with the increase of Co substitution when x≤0.10, but increases when x〉0.10.
基金supported by the Shandong provincial key research and development plan(Grant No.2022CXPT045)Taishan Scholars Program(Grant No.tstp20221130).
文摘BiFeO_(3)(BFO),Mn-doped-BFO(BFMO),Ti-doped-BFO(BFTO),and(Mn,Ti)-codoped-BFO(BFMTO)thin films are fabricated on the Pt/TiO_(2)/SiO_(2)/Si substrates via a sol–gel method combined with spin-coating and the subsequent layer-by-layer annealing technique.Compared with BFO film,the BFMTO film exhibits the lowest leakage current density(-10^(-4) A/cm^(2)@290 kV/cm).Notably,the polarization–electric field(P–E)loop of BFMTO film exhibits a positive displacement along the x-axis due to the existence of internal bias electric field,which is in agreement with the results of the PFM phase and amplitude curves.Especially,a very prominent inverse piezoelectric constant of d_(33)-160 pm/V was obtained,which overcomes other related thin films.The internal bias electric field of BFMTO film can be caused by the different work functions of the thin film and the bottom electrode,accumulation of oxygen vacancies and the formation of defect dipoles.Besides,the internal bias electric field of BFMTO film has a good stability at the same electric field after experiencing the test cycle from low electric field to high electric field(400–1900 kV/cm).These results indicate that self-polarized BFMTO film can be integrated to devices without additional polarization process,and have a wide range of application in microelectromechanical systems.
基金Supported by National Natural Science Foundation of China(Grant No.51201154)
文摘There are few relevant researches on coils by tempering,and the variations of microstructure and properties of steel coil during the tempering process also remain unclear.By using thermo-mechanical control process（TMCP）technology,Mn-Ti typical HSLA steel coils with yield strength of 920 MPa are produced on the 2250 hot rolling production line.Then,the samples are taken from the coils and tempered at the temperatures of 220℃,350℃,and 620℃respectively.After tempering the strength,ductility and toughness of samples are tested,and meanwhile microstructures are investigated.Precipitates initially emerge inside the ferrite laths and the density of the dislocation drops.Then,the lath-shaped ferrites begin to gather,and the retained austenite films start to decompose.Finally,the retained austenite films are completely decomposed into coarse and short rod-shape precipitates composed of C and Ti compounds.The yield strength increases with increasing tempering temperature due to the pinning effect of the precipitates,and the dislocation density decreases.The yield strength is highest when the steel is tempered at 220℃because of pinning of the precipitates to dislocations.The total elongation increases in all samples because of the development of ferrites during tempering.The tensile strength and impact absorbed energy decline because the effect of impeding crack propagation weakens as the retained austenite films completely decompose and the precipitates coarsen.This paper clarifies the influence of different tempering temperatures on phase transformation characteristics and process of Mn-Ti typical multiphase steels,as well as its resulting performance variation rules.
基金supported by the National Natural Science Foundation of China (Grant No. 11034004)National Science Fund for Distinguished Young Scholars (Grant No. 50925103)+1 种基金Key Grant Project of Chinese Ministry of Education (Grant No. 309027)the Fundamental Research Funds for the Central Universities (Grant No. lzujbky-2010-219)
文摘We review our works that focus on the microwave magnetic properties of metallic, ferrite and granular thin films. Soft magnetic material with large permeability and low energy loss in the GHz range is a challenge for the inforcom technologies. GHz magnetic properties of the soft magnetic thin films with in-plane anisotropy were investigated. It is found that several hundreds of permeability at the GHz frequency was achieved for Col00_xZrx and Co90Nbl0 metallic thin films because of their high satu- ration magnetization, and an adjustable resonance frequency from 1.3 to 4.9 GHz was obtained. Compared with the metallic thin films, the weaker saturation magnetization of Ni-Zn ferrite thin films results in several tens of permeability at the GHz frequency, but the larger resistivity of the ferrite prepared in situ without any heating treatments has lower energy loss. In order to obtain materials with large permeability and low energy loss in the GHz range, the [CoFe-NiZn ferrite] composite granular thin films were investigated, where the advantage of higher saturation magnetization for the metallic alloy and the high resis- tivity as well as high saturation magnetization for the ferrite results in a good GHz magnetic performance.
