In this paper a systematic ferromagnetic resonance study shows that an in-plane magnetic anisotropy in the patterned micron octagon permalloy （Ni80Fe20） elements is mainly determined by the element geometry. The eas...In this paper a systematic ferromagnetic resonance study shows that an in-plane magnetic anisotropy in the patterned micron octagon permalloy （Ni80Fe20） elements is mainly determined by the element geometry. The easy-axis is along the edge of the elements, and the hard-axis is along the diagonal. The shape anisotropy of the octagon elements is determined by square and equilateral octagon, and the theoretical calculation was studied on the shape anisotropy. The shape anisotropy of rectangular was calculated by using the same theory.展开更多
A general model of a hybrid inteffacial domain wall （HIDW） in ferromagnetic/antiferromagnetic exchange biased bilayers is proposed, where an inteffacial domain wall is allowed to extend into either the ferromagnetic...A general model of a hybrid inteffacial domain wall （HIDW） in ferromagnetic/antiferromagnetic exchange biased bilayers is proposed, where an inteffacial domain wall is allowed to extend into either the ferromagnetic or antiferromagnetic layer or across both. The proposition is based on our theoretical investigation on thickness and field dependences of ferromagnetic domain wall （FMDW） and antiferromagnetic domain wall （AFDW）, respectively. Good match of the simulation to the hysteresis loops of a series of NiFe/FeMn exchange-biased bilayers confirms the existence of the HIDW, where the AFDW part is found to preferentially occupy the entire antiferromagnetic layer while the FMDW shrinks with the increased magnetic field as expected. The observed asymmetry between the ascending and descending branches of the hysteresis loop is explained naturally as a consequence of different partition ratios between AFDW and FMDW.展开更多
The dependence of giant magnetoresistance of sputtered granular type(Co-Ag)/Ag multilayers on the thickness of Ag layers and magnetic layers with varying Co content in the magnetic layers was studied.The magnetoresist...The dependence of giant magnetoresistance of sputtered granular type(Co-Ag)/Ag multilayers on the thickness of Ag layers and magnetic layers with varying Co content in the magnetic layers was studied.The magnetoresistance ratioΔR/R was found to be enhanced by 2-7 times comparing with the single layer granular films.The enhancement was explained by the antiferromagnetic coupling due to magnetostatic interaction between the Co clusters in neighboring magnetic layers.展开更多
The hysteresis loop and Mdssbauer spectrum of the heat treated Nd_(3)Fe_(81)B_(16) alloy ribbons annealing at 660℃ for lOmin.have been measured.A coercive field of about 2kOe and an energy product of about 8MGOe are ...The hysteresis loop and Mdssbauer spectrum of the heat treated Nd_(3)Fe_(81)B_(16) alloy ribbons annealing at 660℃ for lOmin.have been measured.A coercive field of about 2kOe and an energy product of about 8MGOe are obtained at room temperature.X-ray diffraction and Mdssbauer spectrum analyses show that the high coercivity may originate from the Fe_(3)B phase containing Nd.The value of remanence and energy product in this alloy are much higher than those of anisotropic BaFe_(12)O_(19) ferrite.It may be used as a cheap permanent magnet.展开更多
A calculation of the magnetic single-ion anisotropy in hematite has been made.The results show that an equivalent single-ion anisotropy field Hsi(=103.8×10^(2) Oe)exists along the c-axis at T=0K.The Morin transit...A calculation of the magnetic single-ion anisotropy in hematite has been made.The results show that an equivalent single-ion anisotropy field Hsi(=103.8×10^(2) Oe)exists along the c-axis at T=0K.The Morin transition in hematite could be explained by our results in conjunction with the calculated H_(md) by Artman et al.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 50171020） and the Foundation for youth of Liaocheng University （Grant No X051050）.
文摘In this paper a systematic ferromagnetic resonance study shows that an in-plane magnetic anisotropy in the patterned micron octagon permalloy （Ni80Fe20） elements is mainly determined by the element geometry. The easy-axis is along the edge of the elements, and the hard-axis is along the diagonal. The shape anisotropy of the octagon elements is determined by square and equilateral octagon, and the theoretical calculation was studied on the shape anisotropy. The shape anisotropy of rectangular was calculated by using the same theory.
基金Project supported by the National Basic Research Program,China(Grant No.2010CB923404)the National Natural Science Foundation for Young Scientists of China(Grant No.61306121)the China Postdoctoral Science Foundation(Grant No.2013M541580)
文摘A general model of a hybrid inteffacial domain wall （HIDW） in ferromagnetic/antiferromagnetic exchange biased bilayers is proposed, where an inteffacial domain wall is allowed to extend into either the ferromagnetic or antiferromagnetic layer or across both. The proposition is based on our theoretical investigation on thickness and field dependences of ferromagnetic domain wall （FMDW） and antiferromagnetic domain wall （AFDW）, respectively. Good match of the simulation to the hysteresis loops of a series of NiFe/FeMn exchange-biased bilayers confirms the existence of the HIDW, where the AFDW part is found to preferentially occupy the entire antiferromagnetic layer while the FMDW shrinks with the increased magnetic field as expected. The observed asymmetry between the ascending and descending branches of the hysteresis loop is explained naturally as a consequence of different partition ratios between AFDW and FMDW.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19754001 and 59392800,and Shanghai Research Center for Applied Physics.
文摘The dependence of giant magnetoresistance of sputtered granular type(Co-Ag)/Ag multilayers on the thickness of Ag layers and magnetic layers with varying Co content in the magnetic layers was studied.The magnetoresistance ratioΔR/R was found to be enhanced by 2-7 times comparing with the single layer granular films.The enhancement was explained by the antiferromagnetic coupling due to magnetostatic interaction between the Co clusters in neighboring magnetic layers.
文摘The hysteresis loop and Mdssbauer spectrum of the heat treated Nd_(3)Fe_(81)B_(16) alloy ribbons annealing at 660℃ for lOmin.have been measured.A coercive field of about 2kOe and an energy product of about 8MGOe are obtained at room temperature.X-ray diffraction and Mdssbauer spectrum analyses show that the high coercivity may originate from the Fe_(3)B phase containing Nd.The value of remanence and energy product in this alloy are much higher than those of anisotropic BaFe_(12)O_(19) ferrite.It may be used as a cheap permanent magnet.
文摘A calculation of the magnetic single-ion anisotropy in hematite has been made.The results show that an equivalent single-ion anisotropy field Hsi(=103.8×10^(2) Oe)exists along the c-axis at T=0K.The Morin transition in hematite could be explained by our results in conjunction with the calculated H_(md) by Artman et al.
