Magnetic anisotropy manipulation and interfacial coupling in Sm3Fe5O12 films and CoFe/Sm3Fe5O12 heterostructures

The magnetic anisotropy manipulation in the Sm₃Fe₅O₁₂ (SmIG) films and its effect on the interfacial spin coupling in the CoFe/SmIG heterostructures were studied carefully. By switching the orientation of the Gd₃Ga₅O₁₂ substrates from (111) to (001), the magnetic anisotropy of obtained SmIG films shifts from in-plane to out-of-plane. Similar results can also be obtained in the films on Gd₃Sc₂Ga₃O₁₂ substrates, which identifies the universality of such orientation-induced magnetic anisotropy switching. Additionally, the interfacial spin coupling and magnetic anisotropy switching effect on the spin wave in CoFe/SmIG magnetic heterojunctions have also been explored by utilizing the time-resolved magneto-optical Kerr effect technique. It is intriguing to find that both the frequency and effective damping factor of spin precession in CoFe/SmIG heterojunctions can be manipulated by the magnetic anisotropy switching of SmIG films. These findings not only provide a route for the perpendicular magnetic anisotropy acquisition but also give a further path for spin manipulation in magnetic films and heterojunctions.     

基于二次谐波产生技术的BaTiO3薄膜对称性研究

光学二次谐波产生技术是研究材料极化特性和对称性的重要工具,利用搭建的显微二次谐波产生光路,对生长在SrTiO3衬底上的BaTiO3薄膜样品进行了二次谐波产生测试.结果 表明,BaTiO3薄膜在面内方向具有二重旋转对称性.在四种偏振模式下测量了样品的二次谐波信号,结果表明,随着基频光入射功率的变化,二次谐波强度的图样也发...     

Transient Photoconductivity in LaRhO_3 Thin Film

High-quality epitaxial LaRhO_3(LRO) thin films on SrTiO_3(110) single-crystalline substrates are fabricated by pulsed laser deposition and their photoconductivity properties are studied. The transient photoconductivity(TPC) effect is found in this semiconductor LRO film at room temperature. The magnitude of TPC increases almost linearly with the laser power intensities and the photon energies in visible light range. Moreover, the difference in the TPC results under two airflow conditions confirms that both intrinsic photoinduced carrier accumulation and extrinsic photoinduced heating effects contribute to the magnitude of TPC effect.     

Ho1–xYxFeO3单晶自旋重取向的掺杂效应与磁控效应的太赫兹光谱

利用自研的磁场下太赫兹时域光谱(terahertz time-domain spectroscopy,THz-TDS),系统研究了磁场与非磁性Y³⁺离子掺杂对HoFeO₃单晶中自旋态以及自旋重取向的影响.结果表明Y³⁺掺杂可以在不改变自旋重取向类型情况下,有效降低自旋重取向温区,而且还能降低Ho_1-xY_xFeO₃单晶中低温区准铁磁模式(q-FM,quasi-ferromagnetic mode)自旋共振频率以及提升高温区的准反铁磁模式(q-AFM,quasi-antiferromagnetic mode)自旋共振频率.在沿(110)方向施加外加磁场(JIDC)的情况下,一方面,发现磁场不仅能有效调控Ho_1-xY_xFeO₃单晶中的q-FM共振频率,而且还能诱导出自旋重取向;另一方面,发现温度越接近自旋重取向温区时,磁诱导自旋重取向的发生越容易,而且磁诱导效应的临界磁场强度随Y³⁺