Magnetic domain structures and their evolution in quasi-two-dimensional ferromagnet Cr5Te8

Abstract

The magnetic domain morphology and its evolution process of quasi-two-dimensional (quasi-2D) ferromagnet Cr5Te8 have been studied by microscopic magneto-optic Kerr imaging technique. With variation of external magnetic field, dendritic type domains grow and distribute randomly with negligible pinning effect and obvious hysteresis. Some dendritic domain branches connect to each other with an adjacent angle either 60° or 120°. Moreover, dendritic branches can connect end-to-end to form arched chains and hexagonal rings. Such similarity between macroscopic domain morphology and the arrangement of Cr atoms in the Cr5Te8 crystal indicates that the magnetic domain evolution is tightly related to the in-plane crystal structure, implying a large anisotropy of in-plane magnetic exchange energy in this quasi-2D crystal. These observations provide a microscopic foundation for the understanding and controlling of the magnetic domains in quasi-2D magnets.