钇铁石榴石(yttrium iron garnet,YIG)的自旋输运特性一直是自旋电子学的研究重点之一.Bi作为YIG最常见的掺杂元素,其薄膜Bi_(x)Y_(3-x)Fe_(5)O_(12)的磁光特性已经被广泛研究.但Bi^(3+)取代Y^(3+)对YIG自旋输运的影响规律还没有被系统...钇铁石榴石(yttrium iron garnet,YIG)的自旋输运特性一直是自旋电子学的研究重点之一.Bi作为YIG最常见的掺杂元素,其薄膜Bi_(x)Y_(3-x)Fe_(5)O_(12)的磁光特性已经被广泛研究.但Bi^(3+)取代Y^(3+)对YIG自旋输运的影响规律还没有被系统地研究过.本文利用溶液旋涂法制备了不同掺杂比的Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜,并研究Bi掺杂对YIG薄膜形貌结构和自旋输运性能的影响.结果表明Bi掺杂没有改变YIG的晶体结构,掺杂比上升令薄膜的吸收强度增大,带隙减小.XPS表明了Bi^(3+)和Bi^(2+)的存在.Bi掺杂在自旋输运上的调控体现在Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜的磁振子扩散长度相比纯YIG薄膜有所减小.同时研究发现Pt/Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜中依然可以检测到明显的自旋霍尔磁电阻,并在x=0.3时振幅最大.展开更多
In this work,we report the reorientation of magnetization by spin-orbit torque(SOT)in YIG/Pt bilayers.The SOT is investigated by measuring the spin Hall magnetoresistance(SMR),which is highly sensitive to the directio...In this work,we report the reorientation of magnetization by spin-orbit torque(SOT)in YIG/Pt bilayers.The SOT is investigated by measuring the spin Hall magnetoresistance(SMR),which is highly sensitive to the direction of magnetic moment of YIG.An external in-plane rotating magnetic field which is applied to the YIG/Pt bilayers,and the evolutions of SMR under different injected currents in the Pt layer,result in deviation of SMR curve from the standard shape.We conclude that the SOT caused by spin accumulation near the interface between YIG and Pt can effectively reorient the inplane magnetic moment of YIG.This discovery provides an effective way to modulate YIG magnetic moments by electrical methods.展开更多
In the previous study of longitudinal spin Seebeck effect（LSSE）, the thermal gradient was often generated by inserting the sample between the cool bath and the hot bath. For practical use, this method is too cumbers...In the previous study of longitudinal spin Seebeck effect（LSSE）, the thermal gradient was often generated by inserting the sample between the cool bath and the hot bath. For practical use, this method is too cumbersome to be easily integrated into modern electrical circuits. Since the laser can be easily focused into a small region, it will be more convenient and friendly to the integrated circuit. In this paper, we systematically investigate the LSSE and spin Hall magnetoresistance（SMR） of the Pt/Y_3 Fe_5 O_（12） heterostructure under focused laser-heating. We find that the extremely large voltage of inverse spin Hall effect（VISHE） can be obtained by reducing the diameter of laser or increasing the number of light spots.Meanwhile, even under the illumination of the ultraviolet light which will excite the electron from the valence band to the conduction band in yttrium iron garnet（YIG）, the magnitude of SMR is nearly constant. It indicates that the spin transport behavior of the adjacent Pt is independent of the electron configuration of YIG. The laser-heating method to generate LSSE will be very promising for modern integrated electronic circuits and will promote the application of spin caloritronics in practice.展开更多
文摘钇铁石榴石(yttrium iron garnet,YIG)的自旋输运特性一直是自旋电子学的研究重点之一.Bi作为YIG最常见的掺杂元素,其薄膜Bi_(x)Y_(3-x)Fe_(5)O_(12)的磁光特性已经被广泛研究.但Bi^(3+)取代Y^(3+)对YIG自旋输运的影响规律还没有被系统地研究过.本文利用溶液旋涂法制备了不同掺杂比的Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜,并研究Bi掺杂对YIG薄膜形貌结构和自旋输运性能的影响.结果表明Bi掺杂没有改变YIG的晶体结构,掺杂比上升令薄膜的吸收强度增大,带隙减小.XPS表明了Bi^(3+)和Bi^(2+)的存在.Bi掺杂在自旋输运上的调控体现在Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜的磁振子扩散长度相比纯YIG薄膜有所减小.同时研究发现Pt/Bi_(x)Y_(3-x)Fe_(5)O_(12)薄膜中依然可以检测到明显的自旋霍尔磁电阻,并在x=0.3时振幅最大.
基金Project supported by the Natural Science Foundation of Shaanxi Province,China(Grant No.2020JM-088)the National Natural Science Foundation of China(Grant Nos.51572222,51701158,and 51872241)the Fundamental Research Funds for the Central Universities,China(Grant Nos.3102017jc01001 and 310201911cx044).
文摘In this work,we report the reorientation of magnetization by spin-orbit torque(SOT)in YIG/Pt bilayers.The SOT is investigated by measuring the spin Hall magnetoresistance(SMR),which is highly sensitive to the direction of magnetic moment of YIG.An external in-plane rotating magnetic field which is applied to the YIG/Pt bilayers,and the evolutions of SMR under different injected currents in the Pt layer,result in deviation of SMR curve from the standard shape.We conclude that the SOT caused by spin accumulation near the interface between YIG and Pt can effectively reorient the inplane magnetic moment of YIG.This discovery provides an effective way to modulate YIG magnetic moments by electrical methods.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604265,51471134,51572222,and 11704386)the Fundamental Research Funds for the Central Universities,China(Grant Nos.3102018zy044 and 3102017jc01001)
文摘In the previous study of longitudinal spin Seebeck effect（LSSE）, the thermal gradient was often generated by inserting the sample between the cool bath and the hot bath. For practical use, this method is too cumbersome to be easily integrated into modern electrical circuits. Since the laser can be easily focused into a small region, it will be more convenient and friendly to the integrated circuit. In this paper, we systematically investigate the LSSE and spin Hall magnetoresistance（SMR） of the Pt/Y_3 Fe_5 O_（12） heterostructure under focused laser-heating. We find that the extremely large voltage of inverse spin Hall effect（VISHE） can be obtained by reducing the diameter of laser or increasing the number of light spots.Meanwhile, even under the illumination of the ultraviolet light which will excite the electron from the valence band to the conduction band in yttrium iron garnet（YIG）, the magnitude of SMR is nearly constant. It indicates that the spin transport behavior of the adjacent Pt is independent of the electron configuration of YIG. The laser-heating method to generate LSSE will be very promising for modern integrated electronic circuits and will promote the application of spin caloritronics in practice.
