Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high-density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by m...Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high-density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by magnetron sputtering at room temperature. The influences of N dopant on the magnetic anisotropy of the multilayers were investigated by preparing the sample with N incorporation. The results indicate that when sputtering W target with only argon gas(Ar), Ta/W/Co/Pt sample shows inplane magnetic anisotropy(IMA). When sputtering W target at a different amount of N_(2) and Ar atmosphere, it can induce perpendicular magnetic anisotropy(PMA) for proper N-doped Ta/W(N)/Co/Pt sample. When the gas flow ratio of Ar:N_(2) is 16:6, the effective magnetic anisotropy constant reach its maximum value of 1.68×10^(5) J·m^(-3),which enhanced by about 400% than our past works(annealing treatment is necessary to induce PMA in Pt/Co/MgO system). X-ray diffraction(XRD) and X-ray reflection(XRR) results demonstrate that N dopants can effectively promote the formation of b-W phase and reduce the roughness of W(N)/Co interface, which are beneficial for PMA. X-ray electron spectroscopy(XPS) analysis reveals that N doping redistributes Co charges, nitrogen ions participate in electron allocation of Co and attract some electrons of Co to form orbital hybridization between Co3 d and N 2 p. This may be another important reason for the PMA formation.展开更多
The anisotropic magnetoresistance film is an important core material for developing the magnetic sensors.Here,Ta(5)/Mg O(3)/Ni Fe(10)/Mg O(3)/Ta(3)multilayers(in nanometer)were prepared by magnetron sputtering and fur...The anisotropic magnetoresistance film is an important core material for developing the magnetic sensors.Here,Ta(5)/Mg O(3)/Ni Fe(10)/Mg O(3)/Ta(3)multilayers(in nanometer)were prepared by magnetron sputtering and further applied to construct a sensor element by combining with the Wheatstone bridge.The 1/f noise of the sensor element was greatly reduced by three orders of magnitude after annealing at 400℃for 7200 s,which was mainly due to the significant microstructural changes during the annealing.However,when the sensor element was applied to detect the magnetic signal of a magnetic code disk with 512 N-S magnetic poles,the output voltage signal of the sensor displayed a large fluctuation of±0.05 V.In order to reduce the voltage fluctuation,a magnetic sensor chip by using a parallelly arranged multipath Wheatstone bridges and auto-gain compensation structure was designed,and magnetic sensor elements and the high-performance computing drive module were prepared.The output voltage fluctuation of the magnetic sensor was reduced by about 90%and approached to±0.005 V.These findings provide an important basis for the practical application of Ni Fe-based magnetic sensing film materials.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2019YFB2005800)the National Science Foundation of China(Nos.51871017,51871018 and 52071025)+2 种基金Beijing Natural Science Foundation(No.2192031)the Fundamental Research Funds for the Central Universities(No.FRF-TP-19-011B1)the Foundation of Beijing Key Laboratory of Metallic Materials and Processing for Modern Transportation。
文摘Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high-density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by magnetron sputtering at room temperature. The influences of N dopant on the magnetic anisotropy of the multilayers were investigated by preparing the sample with N incorporation. The results indicate that when sputtering W target with only argon gas(Ar), Ta/W/Co/Pt sample shows inplane magnetic anisotropy(IMA). When sputtering W target at a different amount of N_(2) and Ar atmosphere, it can induce perpendicular magnetic anisotropy(PMA) for proper N-doped Ta/W(N)/Co/Pt sample. When the gas flow ratio of Ar:N_(2) is 16:6, the effective magnetic anisotropy constant reach its maximum value of 1.68×10^(5) J·m^(-3),which enhanced by about 400% than our past works(annealing treatment is necessary to induce PMA in Pt/Co/MgO system). X-ray diffraction(XRD) and X-ray reflection(XRR) results demonstrate that N dopants can effectively promote the formation of b-W phase and reduce the roughness of W(N)/Co interface, which are beneficial for PMA. X-ray electron spectroscopy(XPS) analysis reveals that N doping redistributes Co charges, nitrogen ions participate in electron allocation of Co and attract some electrons of Co to form orbital hybridization between Co3 d and N 2 p. This may be another important reason for the PMA formation.
基金financially supported by the National Key Research and Development Program of China(Nos.2019YFB2005800 and 2019YFB1309902)the National Science Foundation of China(Nos.51871017 and 51871018)+3 种基金Beijing Natural Science Foundation(No.2192031)the Science and Technology Innovation Team Program of Foshan(No.FSOAA-KJ919-44020087)the Fundamental Research Funds for the Central Universities(No.FRF-TP-19-011B1)the Foundation of Beijing Key Laboratory of Metallic Materials and Processing for Modern Transportation。
文摘The anisotropic magnetoresistance film is an important core material for developing the magnetic sensors.Here,Ta(5)/Mg O(3)/Ni Fe(10)/Mg O(3)/Ta(3)multilayers(in nanometer)were prepared by magnetron sputtering and further applied to construct a sensor element by combining with the Wheatstone bridge.The 1/f noise of the sensor element was greatly reduced by three orders of magnitude after annealing at 400℃for 7200 s,which was mainly due to the significant microstructural changes during the annealing.However,when the sensor element was applied to detect the magnetic signal of a magnetic code disk with 512 N-S magnetic poles,the output voltage signal of the sensor displayed a large fluctuation of±0.05 V.In order to reduce the voltage fluctuation,a magnetic sensor chip by using a parallelly arranged multipath Wheatstone bridges and auto-gain compensation structure was designed,and magnetic sensor elements and the high-performance computing drive module were prepared.The output voltage fluctuation of the magnetic sensor was reduced by about 90%and approached to±0.005 V.These findings provide an important basis for the practical application of Ni Fe-based magnetic sensing film materials.
