Magnetism and spin dynamics in room-temperature van der Waals magnet Fe5GeTe2
Magnetism and spin dynamics in room-temperature van der Waals magnet Fe5GeTe2
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DOI：
10.1088/2053-1583/ac2028
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发表时间：
2021-10-01
期刊：
影响因子：
5.5
通讯作者：
Li, Peng
中科院分区：
文献类型：
--
作者：
Alahmed, Laith;Nepal, Bhuwan;Li, Peng
二维货车德瓦耳斯（vdWs）材料是近年来研究的热点。然而，这些材料中的大多数具有远低于室温的居里温度，使得将它们纳入器件应用具有挑战性。本文合成了居里温度Tc = 332 K的室温vdW磁性晶体Fe5GeTe2，并利用振动样品磁强计（VSM）和宽带铁磁共振（FMR）谱研究了其磁性。实验是在沿着c轴（H平行于c）和ab平面（H平行于ab）施加外部磁场的情况下进行的，温度范围为300至10 K。我们发现H平行于c和H平行于ab的情况之间存在相当大的Lande g因子差异。在这两种情况下，Lande g因子值偏离g = 2。这表明轨道角动量对磁矩的贡献。铁磁共振测量结果表明，Fe5GeTe2具有与坡莫合金相当的阻尼常数。随着温度的降低，线宽变宽。与VSM数据一起，我们的测量表明，Fe5GeTe2在较低的温度下从铁磁到亚铁磁的转变。我们的实验突出了Fe5GeTe2的磁性状态和自旋散射过程的关键信息，促进了对Fe5GeTe2磁性的理解，从而实现了基于Fe5GeTe2的室温自旋电子器件。
Two-dimensional van der Waals (vdWs) materials have gathered a lot of attention recently. However, the majority of these materials have Curie temperatures that are well below room temperature, making it challenging to incorporate them into device applications. In this work, we synthesized a room-temperature vdW magnetic crystal Fe5GeTe2 with a Curie temperature T-c = 332 K, and studied its magnetic properties by vibrating sample magnetometry (VSM) and broadband ferromagnetic resonance (FMR) spectroscopy. The experiments were performed with external magnetic fields applied along the c-axis (H parallel to c) and the ab-plane (H parallel to ab), with temperatures ranging from 300 to 10 K. We have found a sizable Lande g-factor difference between the H parallel to c and H parallel to ab cases. In both cases, the Lande g-factor values deviated from g = 2. This indicates contribution of orbital angular momentum to the magnetic moment. The FMR measurements reveal that Fe5GeTe2 has a damping constant comparable to Permalloy. With reducing temperature, the linewidth was broadened. Together with the VSM data, our measurements indicate that Fe5GeTe2 transitions from ferromagnetic to ferrimagnetic at lower temperatures. Our experiments highlight key information regarding the magnetic state and spin scattering processes in Fe5GeTe2, which promote the understanding of magnetism in Fe5GeTe2, leading to implementations of Fe5GeTe2 based room-temperature spintronic devices.