Heat capacity and magnetocaloric effect in manganites La0.7Sr0.3-xBaxMnO3

Abstract

Results of an experimental study of the heat capacity (Cp), as well as direct and indirect measurements of the MCE (∆T, ∆S) of La0.7Sr0.3-xBaxMnO3 samples (x = 0, 0.02, 0.05, 0.10) in the temperature range 80–400 K and in magnetic fields up to 1.8 T are presented. It is shown that the partial substitution of barium (Ba) for strontium (Sr) shifts TC and insignificantly decreases the magnetocaloric effect. The maximum value of the change in entropy in a field of 1.8 T is ∆S = 1.6 J/kg·K for x = 0.02. The entropy change associated with the disordering of the magnetic system during the ferromagnetic-paramagnetic phase transition is estimated. © 2021 Pirogov Russian National Research Medical University. All rights reserved.