No reliable thermodynamic analysis has been available so far, though some measurements exist on scientific journals.

A noticeable result is:

A high-resolution version is HERE.

The published version is available HERE (Pages 5241-5255) by payment to Acta Materialia.

Abstract
Published measurements of sulfur vapor pressure were used to determine thermodynamic properties of the Cr-S system.
Statistical thermodynamics was applied to find partition functions, interaction energies, and free energies to characterize
the five phases appearing in the measurements. The free-energy expressions were able to qualitatively indicate
the change in stability of the phases between 873 and 1364 K.