In-situ TEM observations of the crystallization process of solution-prepared MoS2 amorphous particles.

The crystallization of polymer-mixed amorphous molybdenum sulfide was observed in-situ by a TEM equipped with a heated specimen holder. High electron beam irradiation induced the formation of a crystal structure with a lattice spacing of 0.62 nm, which corresponds to the layer spacing of MoS2. With a lower electron dose, a possible new crystal structure of molybdenum sulfide with several fringe spacings was identified at room temperature. An ordered layered structure of MoS2 appeared after annealing at 600 degrees C. The completely different crystal phase found here might be responsible for the high temperature required for the formation of the MoS2 layered structure.