Characterization of room-temperature in-plane magnetization in thin flakes of CrTe$_2$ with a single spin magnetometer

Abstract: We demonstrate room-temperature ferromagnetism with in-plane magnetic anisotropy in thin flakes of the CrTe$_2$ van der Waals ferromagnet. Using quantitative magnetic imaging with a single spin magnetometer based on a nitrogen-vacancy defect in diamond, we infer a room-temperature in-plane magnetization in the range of $M\sim 27$ kA/m for flakes with thicknesses down to $20$ nm. In addition, our measurements indicate that the orientation of the magnetization is not determined solely by shape anisotropy in micron-sized CrTe$_2$ flakes, which suggest the existence of a non-negligible magnetocrystalline anisotropy. These results make CrTe$_2$ a unique system in the growing family of van der Waals ferromagnets, as it is the only material platform known to date which offers an intrinsic in-plane magnetization and a Curie temperature above $300$ K in thin flakes.