The compounds, Cr₂TeO₆(s), Fe₂TeO₆(s) and Ni₃TeO₆(s) were synthesized by solid-state route andcharacterized using X-ray diffraction technique. Thermal expansion of Fe₂TeO₆(s) and Ni₃TeO₆(s)were studied by high temperature X-ray diffraction technique in the temperature range 298–973 K and 298–923 K, respectively. The average volume thermal expansion coefficient of Fe₂TeO₆(s) and Ni₃TeO₆(s) were determined to be 2.46 × 10⁻⁵ and 3.02 × 10⁻⁵K⁻¹, respectively. Heat capacity of Cr₂TeO₆(s),Fe₂TeO₆(s) and Ni₃TeO₆(s) was measured, in the temperature range of 300–870 K, employing temper-ature modulated differential scanning calorimeter. The Gibbs energy of formation of Fe₂TeO₆(s) and Ni₃TeO₆(s) were measured using transpiration method. An empirical function was derived to computeenthalpy of formation of AnTeO₆(s) (where A = various elements of periodic table, n = 2, 3 or 6). Self consis-tent thermodynamic functions of Cr₂TeO₆(s), Fe₂TeO₆(s) and Ni₃TeO₆(s) were calculated. The chemicalpotential diagrams of A–Te–O (A = Cr, Fe, Te) system were also constructed.