As a van der Waals ferromagnet with high Curie temperature,Fe_(5-x)GeTe_(2) has attracted tremendous interests recently.Here,using high-resolution angle-resolved photoemission spectroscopy(ARPES),we systematically inv...As a van der Waals ferromagnet with high Curie temperature,Fe_(5-x)GeTe_(2) has attracted tremendous interests recently.Here,using high-resolution angle-resolved photoemission spectroscopy(ARPES),we systematically investigated the electronic structure of Fe_(5-x)GeTe_(2) 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 Fe_(5-x)GeTe_(2) and the understanding of magnetism in a two-dimensional ferromagnetic system.展开更多
基金the National Key R&D Program of China(Grant No.2017YFA0305400)。
文摘As a van der Waals ferromagnet with high Curie temperature,Fe_(5-x)GeTe_(2) has attracted tremendous interests recently.Here,using high-resolution angle-resolved photoemission spectroscopy(ARPES),we systematically investigated the electronic structure of Fe_(5-x)GeTe_(2) 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 Fe_(5-x)GeTe_(2) and the understanding of magnetism in a two-dimensional ferromagnetic system.
基金supported by the National Key Research and Development Program of China (2017YFA0305400, 2017YFA0304600, 2018YFA0307100, and 2018YFA0305603)the National Natural Science Foundation of China (11774190, 11674229, 11634009, 11774427, 51788104, and 11874035)+1 种基金EPSRC Platform Grant (EP/M020517/1)the support from the Shanghai Pujiang Program (17PJ1406200)。