Park Ji-Ho, Ko Hye-Won, Kim Jeong-Mok, Park Jungmin, Park Seung-Young, Jo Younghun, Park Byong-Guk, Kim Se Kwon, Lee Kyung-Jin, Kim Kab-Jin
Department of Physics, KAIST, Daejeon, 34141, South Korea.
Department of Materials Science and Engineering and KI for Nanocentury, KAIST, Daejeon, 34141, South Korea.
Sci Rep. 2021 Oct 22;11(1):20884. doi: 10.1038/s41598-021-00374-8.
Electrical conduction in magnetic materials depends on their magnetization configuration, resulting in various magnetoresistances (MRs). The microscopic mechanisms of MR have so far been attributed to either an intrinsic or extrinsic origin, yet the contribution and temperature dependence of either origin has remained elusive due to experimental limitations. In this study, we independently probed the intrinsic and extrinsic contributions to the anisotropic MR (AMR) of a permalloy film at varying temperatures using temperature-variable terahertz time-domain spectroscopy. The AMR induced by the scattering-independent intrinsic origin was observed to be approximately 1.5% at T = 16 K and is virtually independent of temperature. In contrast, the AMR induced by the scattering-dependent extrinsic contribution was approximately 3% at T = 16 K but decreased to 1.5% at T = 155 K, which is the maximum temperature at which the AMR can be resolved using THz measurements. Our results experimentally quantify the temperature-dependent intrinsic and extrinsic contributions to AMR, which can stimulate further theoretical research to aid the fundamental understanding of AMR.
磁性材料中的导电取决于其磁化配置，从而产生各种磁阻（MR）。到目前为止，磁阻的微观机制被归因于本征或非本征起源，然而由于实验限制，这两种起源的贡献及其温度依赖性仍然难以捉摸。在本研究中，我们使用变温太赫兹时域光谱，在不同温度下独立探测了坡莫合金薄膜各向异性磁阻（AMR）的本征和非本征贡献。由与散射无关的本征起源引起的AMR在T = 16 K时约为1.5%，并且实际上与温度无关。相比之下，由与散射相关的非本征贡献引起的AMR在T = 16 K时约为3%，但在T = 155 K时降至1.5%，155 K是使用太赫兹测量能够分辨AMR的最高温度。我们的结果通过实验量化了AMR中与温度相关的本征和非本征贡献，这可以激发进一步的理论研究，以帮助从根本上理解AMR。
