Growth of van der Waals magnetic semiconductor materials

Abstract Magnetic order in two-dimensional semiconducting layered materials is extremely rare. This has recently triggered a great interest in a variety of layered magnetic compounds, determining whether their magnetic properties can be retained down to monolayer thickness. The most promising systems are the binary MX3 and ternary MYZ3 compounds, where M is a metal, X is a halogen element, Y = Si, Ge or P, and Z is a chalcogen. The transition metal incorporates the magnetism, by a partially filled d-shell, thus enabling ferroic responses for enhanced functionalities. In most of these systems, the phase diagrams are not known and the crystal growth process is made challenging by the high fugacity of some elements and the high reaction temperature needed. We review the recent progress in crystal growth of various compounds of these families, namely CrI3, CrCl3, CrSiTe3, CrGeTe3, MnPS3 and MnPSe3, for which we used different growth techniques, such as melt growth, physical vapor transport and chemical vapor transport. The growth parameters are summarized and discussed. The characterization of the materials is focusing on the determination of the crystal structure, chemical composition and magnetic properties. In some cases, exfoliated flakes of these crystals have been successfully used for nano-device fabrication.