Synthetic Understanding for Magnetic CrGeTe3 Nanoplatelets

Controlling magnetism down to the nanoscale has the potential to meet the growing needs of increasing computing power without increasing energy requirements through combining memory and logic functions in computing architectures. The synthesis of 2D van der Waals materials that display a long-range ferromagnetic order is limited to mechanical exfoliation of chemical vapor-grown bulk crystals with only a few examples of solution-phase synthesis, impeding any scale-up capabilities for their incorporation in these devices. Here, we have developed a one-pot solution phase method for the synthesis of colloidal 2D van der Waals CrGeTe3 hexagonal nanoplatelets. Through X-ray diffraction and transmission electron microscopy, we confirm the presence of rhombohedral CrGeTe3 with lateral dimensions of >100 nm and thickness ranging from 8 to 50 nm. After studying various reaction parameters such as the nature of precursors, reaction temperature, time, and solvent, we offer a potential reaction pathway leading toward the product through an intermediate formation of GeTe seeds. Colloidal CrGeTe3 exhibits magnetic properties to its counterpart grown by chemical vapor deposition with a Curie temperature of 60 K and soft ferromagnetic behavior. This method provides a simplified alternative from complicated self-flux solid-state methods toward synthesizing CrGeTe3 through a one-pot methodology with commercially available precursors.