强磁场下RxEr1-xFeO3晶体的超快光磁研究

Rare-earth orthoferrites with perovskite structure have unique magnetic properties. A series of outstanding achievement about ultrafast opto-magnetism on Rare-earth orthoferrites crystals have been published at Nature, Physics Review Letter, etc. since 2004, including ultrafast laser-induced spin reorientation phase transition and its coherent control by a single laser pulse..Among the orthoferrites family, ErFeO3 displays surprisingly physical properties related to spin. Except pin reorientation phase transition, it shows the negative magnetization and the compensation temperature. The negative magnetization phenomenon is suppressed, and the compensation temperature shifts to higher temperature in higher magnetic field. .In this project, we will systematic investigate RxEr1-xFeO3compounds’ local phase diagrams. Based on the crystallization RxEr1-xFeO3 compounds, High quality ErFeO3 and RxEr1-xFeO3 crystals will be grow through optimizing growth process. Meanwhile, the ultrafast opto-magnetism, nonlinear magneto-optics, magnetic dynamics etc. physical properties will also be systematic investigated in high magnetic field. It will reveal the physical mechanism of equilibrium and non-equilibrium magnetic phase transitions in RxEr1-xFeO3 system, realize controlling in phase transition temperature and magneto-optic property, drive their application at spin device in the future.

2004 年起，《Nature》等知名学术刊物先后报道了关于 RFeO3 的超快自旋重取向以及其相干控制的研究报道，这些发现为超快光磁效应在自旋电子器件中的应用开辟了更为广阔的应用前景。在众多稀土正铁氧体化合物中，ErFeO3单晶除了晶体内部发生了铁离子磁格子自旋重取向现象，还出现负磁化和磁化补偿点等现象。随着外加磁场的增强，其负磁化被抑制，补偿温度点向高温移动。.本项目基于该类材料的现状，选择ErFeO3单晶及掺杂的RxEr1-xFeO3晶体作为研究对象，开展晶体生长及强磁场下超快光磁研究。系统研究 RxEr1-xFeO3晶体的超快光磁行为与强磁场下的磁动力学过程，揭示其平衡及非平衡磁相变的物理机制，实现对材料相变温度和磁光性能的调控，推动该材料将来在自旋电子器件中的应用。

2004 年起，《Nature》等知名学术刊物先后报道了关于 RFeO3 的超快自旋重取向以 及其相干控制的研究报道，这些发现为超快光磁效应在自旋电子器件中的应用开辟了更为广阔的应用前景。在众多稀土正铁氧体化合物中，ErFeO3单晶除了晶体内部发生了铁离子磁格子自 旋重取向现象，还出现负磁化和磁化补偿点等现象。随着外加磁场的增强，其负磁化被抑制， 补偿温度点向高温移动。 .本项目基于该类材料的现状，选择ErFeO3单晶及掺杂的RxEr1-xFeO3晶体作为研究对象，开展晶体生长及强磁场下超快光磁研究。在本项目的资助下，系统研究 RxEr1-xFeO3晶体的超快光磁行为与强磁 场下的磁动力学过程，揭示其平衡及非平衡磁相变的物理机制。其中在Er0.4Dy0.6FeO3晶体中发现了Г3 (Cx, Fy, Az)→Г4 (Gx, Ay, Fz)磁相变，相关研究成果以“The unusual spin reorientation transition and exchange bias effect in Er0.6Dy0.4FeO3 single crystal”发表在Applied Physics Letters, 2020, 116: 192409上。另外通过本课题，构建了中国科学院上海硅酸盐研究所、强磁场科学中心、俄罗斯科学院约飞研究所和白俄罗斯科学院固体和半导体物理研究所在稀土正铁氧体领域的国际合作.