Mechanical properties of niobium disulfide and its hydrated sodium cation intercalation compound

Abstract

Mechanical properties of 2H–NbS2 and its intercalation derivative Nax(H2O)yNbS2 were measured by using nanoindentation techniques. The intercalation chemical process was conducted in solution and the cation–hydrated derivative produced was [Nax(H2O)yNbS2]. It was observed that the intercalation process occurs through the crystal edges producing a wave intercalation's front that moved as the reaction proceeded. The hardness and elastic modulus presented very low values in the intercalated region. The load × displacement curves from nanoindentation tests suggested that intercalation of hydrated sodium ions through the edges caused layer separation even in the nonintercalated region at the center of the crystal. It is important to emphasize that no similar studies were found in the literature about this theme. Intercalation process is very important in several areas, like solid-state batteries, and mechanical properties of these kinds of materials are not completely understood. This study is a new approach to understanding the mechanical behavior of layered materials submitted to an intercalation process.