The temperature dependence of heat capacity of Co7/3Sb2/3O4 has been measured for the first time in the range from (6 to 337) K by precision adiabatic vacuum calorimetry. The experimental data were used to calculate standard thermodynamic functions, namely the heat capacity, enthalpy H degrees(T) - H degrees(0), entropy S degrees(T) - S degrees(0) and Gibbs function G degrees(T) - H degrees(0), for the range from T -> (0 to 337) K. Additional spectroscopic studies were carried out to study the nature of the phase transition at T = 60.3 K. The structure of Co7/3Sb2/3O4 is refined by the Rietveld method: space group F d3m, Z = 8, a = 10.3793(2) , V = 1118.14(4) 3. The high-temperature X-ray diffraction was used for the determination of temperature of high-temperature phase transition and coefficient of thermal expansion. (C) 2014 Elsevier Ltd. All rights reserved.