Tunable Curie temperature in layered ferromagnetic Cr5+xTe8 single crystals

The relatively low Curie temperature (Tc) in recently discovered two-dimensional ferromagnetic (FM) materials has limited their potential applications in designing next generation electronics. Searching for new low-dimensional layered materials with room-temperature Tc is highly needed. Here, we report the study of layered FM materials Cr5+xTe8 (x = −0.10, 0.11, 0.56, 1) in which Tc can be well manipulated by the Cr content. Single crystalline Cr5+xTe8 samples have been synthesized and characterized by energy dispersive x-ray spectroscopy, x-ray diffraction, and magnetization measurements. We have found that Tc increases monotonically with Cr content and reaches 313 K at x = 1. While the FM coupling is enhanced with an increase in the Cr content, the antiferromagnetic (AFM) phase at low temperatures is suppressed. Due to the competition of FM and AFM phases, a wasp-waist loop is observed on isothermal magnetization curves. A magnetic flip occurs by changing the temperature and magnetic field to overcome the flipping energy barrier. Our results indicate that the Cr5+xTe8 system serves as a promising platform to tune the 2D ferromagnetism in layered materials.