Magnetocaloric effect across the coupled structural/magnetocrystalline anisotropy transition in Pr$_{1-x}$Sr$_{x}$CoO$_{3}$ (x=0.3-0.5)

Large magnetocaloric effects (MCE) are often observed in materials exhibiting a first order magnetic transition coupled with a crystal structure change. Since the magnetic and structural changes are coupled, it is difficult to decouple the structural entropy contribution from the magnetic entropy contribution to the total MCE. Therefore a clear understanding of the structural entropy change and its field dependence in such materials is lacking. A recent study revealed that Pr$_{1-x}$Sr$_{x}$CoO$_{3}$ (x$>$0.35) undergo a coupled structural/magnetocrystalline anisotropy transition at T$_{A}$, in addition to the paramagnetic-ferromagnetic transition at T$_{C}$. Since the structural change at T$_{A}$ in PSCO is not associated with any magnetic transition, it is an excellent system for studying the structural entropy change and its contribution to the MCE. We report systematic studies of the MCE in Pr$_{1-x}$Sr$_{x}$CoO$_{3}$ (x=0.3, 0.35, 0.4, 0.5) compounds. The results show significant entropy change at T$_{A}$, whose magnitude can be tuned by controlling the magnetocrystalline anisotropy.