Qian Tiema, Emmanouilidou Eve, Hu Chaowei, Green Jazmine C, Mazin Igor I, Ni Ni
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States.
Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, United States.
Nano Lett. 2022 Jul 13;22(13):5523-5529. doi: 10.1021/acs.nanolett.2c01680. Epub 2022 Jun 22.
Activating metamagnetic transitions between ordered states in van der Waals magnets and devices bring great opportunities in spintronics. We show that external pressure, which enhances the interlayer hopping without introducing chemical disorders, triggers multiple metamagnetic transitions upon cooling in the topological van der Waals magnets Mn(BiSb)Te, where the antiferromagnetic interlayer superexchange coupling competes with the ferromagnetic interlayer coupling mediated by the antisite Mn spins. The temperature-pressure phase diagrams reveal that while the ordering temperature from the paramagnetic to ordered states is almost pressure-independent, the metamagnetic transitions show nontrivial pressure and temperature dependence, even re-entrance. For these highly anisotropic magnets, we attribute the former to the ordering temperature being only weakly dependent on the intralayer parameters and the latter to the parametrically different pressure and temperature dependence of the two interlayer couplings. Our independent probing of these disparate magnetic interactions paves an avenue for efficient magnetic manipulations in van der Waals magnets.
激活范德华磁体和器件中有序态之间的亚磁转变为自旋电子学带来了巨大机遇。我们表明，外部压力在不引入化学无序的情况下增强了层间跳跃，在拓扑范德华磁体Mn(BiSb)Te冷却时触发了多个亚磁转变，其中反铁磁层间超交换耦合与由反位Mn自旋介导的铁磁层间耦合相互竞争。温度-压力相图表明，虽然从顺磁态到有序态的有序温度几乎与压力无关，但亚磁转变表现出非平凡的压力和温度依赖性，甚至出现再入现象。对于这些高度各向异性的磁体，我们将前者归因于有序温度仅微弱地依赖于层内参数，而将后者归因于两种层间耦合在参数上不同的压力和温度依赖性。我们对这些不同磁相互作用的独立探测为范德华磁体中的高效磁操控开辟了一条途径。
