Chinese Physics B 31(5), 057404 (2022)
Kui Huang (黄逵), Zhenxian Li (李政贤), Deping Guo (郭的坪), Haifeng Yang (杨海峰), Yiwei Li (李一苇), Aiji Liang (梁爱基), Fan Wu (吴凡), Lixuan Xu (徐丽璇), Lexian Yang (杨乐仙), Wei Ji (季威), Yanfeng Guo (郭艳峰), Yulin Chen (陈宇林)* and Zhongkai Liu (柳仲楷)*
Abstract
As a van der Waals ferromagnet with high Curie temperature, Fe5–xGeTe2 has attracted tremendous interests recently. Here, using high-resolution angle-resolved photoemission spectroscopy (ARPES), we systematically investigated the electronic structure of Fe5–xGeTe2 crystals and its temperature evolution. Our ARPES measurement reveals two types of band structures from two different terminations with slight kz evolution. Interestingly, across the ferromagnetic transition, we observed the merging of two split bands above the Curie temperature, suggesting the band splitting due to the exchange interaction within the itinerant Stoner model. Our results provide important insights into the electronic and magnetic properties of Fe5–xGeTe2 and the understanding of magnetism in a two-dimensional ferromagnetic system.
