Large magnetocaloric effect has been observed in Mn3O4 around its ferrimagnetic transition at TN = 42.75 K. Field-induced isothermal entropy changes (DeltaS) were derived from both magnetic and calorimetric techniques. The maximum |DeltaS| and adiabatic temperature change ({Delta}Tad) at TN are 11 J kg-1 K-1 and 1.9 K, respectively, for a magnetic field change of 20 kOe. Moreover, it is found that the complex magnetic phase transitions taking place below TN produce additional -but smaller- features on DeltaS(T).
