Husremović Samra, Groschner Catherine K, Inzani Katherine, Craig Isaac M, Bustillo Karen C, Ercius Peter, Kazmierczak Nathanael P, Syndikus Jacob, Van Winkle Madeline, Aloni Shaul, Taniguchi Takashi, Watanabe Kenji, Griffin Sinéad M, Bediako D Kwabena
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
J Am Chem Soc. 2022 Jul 13;144(27):12167-12176. doi: 10.1021/jacs.2c02885. Epub 2022 Jun 22.
Two-dimensional (2D) magnetic crystals hold promise for miniaturized and ultralow power electronic devices that exploit spin manipulation. In these materials, large, controllable magnetocrystalline anisotropy (MCA) is a prerequisite for the stabilization and manipulation of long-range magnetic order. In known 2D magnetic crystals, relatively weak MCA typically results in soft ferromagnetism. Here, we demonstrate that ferromagnetic order persists down to the thinnest limit of FeTaS (Fe-intercalated bilayer 2-TaS) with giant coercivities up to 3 T. We prepare Fe-intercalated TaS by chemical intercalation of van der Waals-layered 2-TaS crystals and perform variable-temperature transport, transmission electron microscopy, and confocal Raman spectroscopy measurements to shed new light on the coupled effects of dimensionality, degree of intercalation, and intercalant order/disorder on the hard ferromagnetic behavior of FeTaS. More generally, we show that chemical intercalation gives access to a rich synthetic parameter space for low-dimensional magnets, in which magnetic properties can be tailored by the choice of the host material and intercalant identity/amount, in addition to the manifold distinctive degrees of freedom available in atomically thin, van der Waals crystals.
二维（2D）磁性晶体有望用于利用自旋操控的小型化和超低功耗电子设备。在这些材料中，大的、可控的磁晶各向异性（MCA）是稳定和操控长程磁序的先决条件。在已知的二维磁性晶体中，相对较弱的MCA通常会导致软铁磁性。在此，我们证明了铁磁序在FeTaS（铁插层双层2-TaS）的最薄极限下仍然存在，其矫顽力高达3 T。我们通过对范德华层状2-TaS晶体进行化学插层来制备铁插层TaS，并进行变温输运、透射电子显微镜和共焦拉曼光谱测量，以揭示维度、插层程度以及插层剂有序/无序对FeTaS硬铁磁行为的耦合效应。更一般地说，我们表明化学插层为低维磁体提供了丰富的合成参数空间，在这个空间中，除了原子级薄的范德华晶体中可用的多种独特自由度外，通过选择主体材料和插层剂的身份/数量还可以调整磁性。
