The giant magneto-impedance(GMI)effect has been investigated in sandwiched FeCuCrVSiB films annealed at 300℃ for 1.5 h.The frequency and field dependences of the GMI have been observed in the frequency range from 50 ...The giant magneto-impedance(GMI)effect has been investigated in sandwiched FeCuCrVSiB films annealed at 300℃ for 1.5 h.The frequency and field dependences of the GMI have been observed in the frequency range from 50 kHz to 13 MHz.The GMI ratio increases at first with increasing frequency,and reaches its maximum value of 136%at a very low characteristic frequency of about 4 MHz,and then decreases with further increasing frequency.These superior properties are related to the special structure of the sandwiched films.展开更多
Amorphous MnxGe1-x：H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron co- sputtering show global ferromagnetism with positive coercivity at low temperatures. With increasing temperature...Amorphous MnxGe1-x：H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron co- sputtering show global ferromagnetism with positive coercivity at low temperatures. With increasing temperature, the coercivity of MnxGe1-x：H films first changes from positive to negative, and then back to positive again, which was not found in the corresponding MnxGe1-x and other ferromagnetic semiconductors before. For Mn0.4Ge0.6：H film, the inverted Hall loop is also observed at 30 K, which is consistent with the negative coercivity. The negative coercivity is explained by the antiferromagnetic exchange coupling between the H-rich ferromagnetic regions separated by the H-poor non-ferromagnetic spacers. Hydrogenation is a useful method to tune the magnetic properties of MnxGe1-x films for the application in spintronics.展开更多
FexGe1−x/Ge amorphous heterojunction diodes with p-FexGe1−x ferromagnetic semiconductor layers are grown on single-crystal Ge substrates of p-type,n-type and intrinsic semiconductors,respectively.The I–V curves of p−...FexGe1−x/Ge amorphous heterojunction diodes with p-FexGe1−x ferromagnetic semiconductor layers are grown on single-crystal Ge substrates of p-type,n-type and intrinsic semiconductors,respectively.The I–V curves of p−Fe_(0.4)Ge_(0.6)/p−Ge diodes only show slight changes with temperature or with magnetic field.For the p-Fe_(0.4)Ge_(0.6)/n−Ge diode,good rectification is maintained at room temperature.More interestingly,the I–V curve of the p−Fe0.4Ge0.6/i-Ge diode can be tuned by the magnetic field,indicating a large positive magnetoresistance.The resistances of the junctions decrease with the increasing temperature,suggesting a typical semiconductor transport behavior.The origin of the positive magnetoresistance is discussed based on the effect of the electric and magnetic field on the energy band structures of the interface.展开更多
Giant magneto-impedance effects have been observed in as-deposited amorphous FeCuNbSiB/Cu/FeCuNbSiB and FeCuNbSiB/SiO_(2)/Ag/SiO_(2)/FeCuNbSiB multilayered films.The films were deposited onto Si substrates by radio fr...Giant magneto-impedance effects have been observed in as-deposited amorphous FeCuNbSiB/Cu/FeCuNbSiB and FeCuNbSiB/SiO_(2)/Ag/SiO_(2)/FeCuNbSiB multilayered films.The films were deposited onto Si substrates by radio frequency sputtering.In FeCuNbSiB/Cu/FeCuNbSiB films,maximum giant magneto-impedance ratios as large as 32%and 11%were obtained at 13 MHz in the longitudinal and transverse fields,respectively.In FeCuNbSiB/SiO_(2)/Ag/SiO_(2)/FeCuNbSiB films,the maximum giant magneto-impedance ratios were 47%and 57%at the same frequency for the two cases,which are much larger than those obtained in the annealed single layer Hlms.展开更多
Longitudinal and transverse magneto-impedance effects have been observed in amorphous FeCuNbSiB films made by radio frequency sputtering.Large magneto-impedance values have been obtained at lower frequencies.The field...Longitudinal and transverse magneto-impedance effects have been observed in amorphous FeCuNbSiB films made by radio frequency sputtering.Large magneto-impedance values have been obtained at lower frequencies.The field dependence and frequency dependence of the magneto-impedance are studied.The field dependence of effective permeabilityμe is also discussed.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.59981004the Doctoral Training Foundation of the National Education Commission under Grant No.9704225.
文摘The giant magneto-impedance(GMI)effect has been investigated in sandwiched FeCuCrVSiB films annealed at 300℃ for 1.5 h.The frequency and field dependences of the GMI have been observed in the frequency range from 50 kHz to 13 MHz.The GMI ratio increases at first with increasing frequency,and reaches its maximum value of 136%at a very low characteristic frequency of about 4 MHz,and then decreases with further increasing frequency.These superior properties are related to the special structure of the sandwiched films.
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 11204164)the National Natural Science Foundation of China (Grant No. 11174184)+1 种基金the National Basic Research Program of China (Grants Nos. 2013CB922303 and 2009CB929202)the National Funds for Distinguished Young Scholars of China (Grant No. 51125004)
文摘Amorphous MnxGe1-x：H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron co- sputtering show global ferromagnetism with positive coercivity at low temperatures. With increasing temperature, the coercivity of MnxGe1-x：H films first changes from positive to negative, and then back to positive again, which was not found in the corresponding MnxGe1-x and other ferromagnetic semiconductors before. For Mn0.4Ge0.6：H film, the inverted Hall loop is also observed at 30 K, which is consistent with the negative coercivity. The negative coercivity is explained by the antiferromagnetic exchange coupling between the H-rich ferromagnetic regions separated by the H-poor non-ferromagnetic spacers. Hydrogenation is a useful method to tune the magnetic properties of MnxGe1-x films for the application in spintronics.
基金Supported by the National Basic Research Program of China under Grant Nos.2007CB924903 and 2009CB929202the National Natural Science Foundation of China under Grant No.10974120the Outstanding Youth Foundation of Shandong Province under Grant No.JQ200901.
文摘FexGe1−x/Ge amorphous heterojunction diodes with p-FexGe1−x ferromagnetic semiconductor layers are grown on single-crystal Ge substrates of p-type,n-type and intrinsic semiconductors,respectively.The I–V curves of p−Fe_(0.4)Ge_(0.6)/p−Ge diodes only show slight changes with temperature or with magnetic field.For the p-Fe_(0.4)Ge_(0.6)/n−Ge diode,good rectification is maintained at room temperature.More interestingly,the I–V curve of the p−Fe0.4Ge0.6/i-Ge diode can be tuned by the magnetic field,indicating a large positive magnetoresistance.The resistances of the junctions decrease with the increasing temperature,suggesting a typical semiconductor transport behavior.The origin of the positive magnetoresistance is discussed based on the effect of the electric and magnetic field on the energy band structures of the interface.
基金Supported by the National Natural Science Foundation of China under Grant No.59671022the Doctoral Training Foundation of the National Education Commission under Grant No.97042205.
文摘Giant magneto-impedance effects have been observed in as-deposited amorphous FeCuNbSiB/Cu/FeCuNbSiB and FeCuNbSiB/SiO_(2)/Ag/SiO_(2)/FeCuNbSiB multilayered films.The films were deposited onto Si substrates by radio frequency sputtering.In FeCuNbSiB/Cu/FeCuNbSiB films,maximum giant magneto-impedance ratios as large as 32%and 11%were obtained at 13 MHz in the longitudinal and transverse fields,respectively.In FeCuNbSiB/SiO_(2)/Ag/SiO_(2)/FeCuNbSiB films,the maximum giant magneto-impedance ratios were 47%and 57%at the same frequency for the two cases,which are much larger than those obtained in the annealed single layer Hlms.
基金Supported by the National Natural Science Foundation of China under Grant No.59671022the Doctoral Training Foundation of the National Education Commission under Grant No.97042205。
文摘Longitudinal and transverse magneto-impedance effects have been observed in amorphous FeCuNbSiB films made by radio frequency sputtering.Large magneto-impedance values have been obtained at lower frequencies.The field dependence and frequency dependence of the magneto-impedance are studied.The field dependence of effective permeabilityμe is also discussed.
