Department of Physics, Chonnam National University, Gwangju 500-757, Korea.
Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
Sci Rep. 2014 Jan 14;4:3680. doi: 10.1038/srep03680.
We report the first case of the successful measurements of a localized spin antiferromagnetic transition in delafossite-type PdCrO2 by angle-resolved photoemission spectroscopy (ARPES). This demonstrates how to circumvent the shortcomings of ARPES for investigation of magnetism involved with localized spins in limited size of two-dimensional crystals or multi-layer thin films that neutron scattering can hardly study due to lack of bulk compared to surface. Also, our observations give direct evidence for the spin ordering pattern of Cr(3+) ions in PdCrO2 suggested by neutron diffraction and quantum oscillation measurements, and provide a strong constraint that has to be satisfied by a microscopic mechanism for the unconventional anomalous Hall effect recently reported in this system.
我们报告了首例通过角分辨光电子能谱（ARPES）成功测量类水滑石型 PdCrO2 中局域自旋反铁磁转变的案例。这展示了如何克服 ARPES 在研究与二维晶体或多层薄膜中局域自旋相关的磁性时的局限性，由于与表面相比缺乏体相，中子散射很难研究这些磁性。此外，我们的观察结果为中子衍射和量子振荡测量所建议的 PdCrO2 中 Cr(3+)离子的自旋有序模式提供了直接证据，并为最近在该体系中报道的非常规反常霍尔效应提供了一个微观机制必须满足的强约束。
