CommentFigure shows the first and second heating process. Sulfidation reaction starts at 360Ž, and continues till 790Ž. During this stage MnP-type VS is formed over the range of 360-470Ž, followed by the phase transition from MnP-type to NiAs-type VS at 506Ž.
The enthalpy of formation@Product is the hexagonal
VS.
The enthalpy of formation becomes ĢHf=32Kcal/mol.
