This paper presents the result of thermodynamic studies on Ge1−xSnxSe2.5 (0 ≤ x ≤ 0.5) glasses using differential scanning calorimetry. The obtained experimental results on phase transformations have been
employed to obtain thermodynamic parameters like entropy difference between metastable states in the glassy region, difference
of Gibbs free energy, specific heat, entropy between the glassy and the crystalline phase and the enthalpy released during
phase transformation (glassy to crystalline). The results yield that, Ge0.7Sn0.3Se2.5 sample is least stable among all the samples. The stability increases on addition of Sn beyond 0.3 at. mass% upto 0.5 at.