CommentFigure shows the first and second heating processes. Sulfidation reaction proceeds by more than 90% over 425-650. Second curve corresponds to the back ground. H=2.06J/g.
The enthalpy of formation@Product is the trigonal
HfS2. A small amount of unreacted Hf is coexisted. The enthalpy of formation, Hf=119.1Kcal/mol
