Magnetocaloric effect and critical behaviour of La0.5Ca0.2Ag0.3MnO3 compound

Abstract

We present a dc magnetization study of the critical phenomena of a manganite oxide La0.5Ca0.2Ag0.3MnO3 single crystal. Based on the assumption of a continuous (second order) manganite transition for our sample, we have determined the critical temperature Tc = 264 K and the critical exponents β=0.18259±0.004 (β: critical exponent for the temperature dependence of spontaneous magnetization just below TC), γ=0.81967±0.0.029 (γ: critical exponent for the inverse initial susceptibility just above TC) and δ=5.45±0.006 (δ: critical exponent for the Widom scaling relation (T = TC)). From the field dependence of the magnetic entropy ΔSMΔSM∝Hn and the relative cooling power (RCP) RCP∝H∧1+1/δ, it was possible to evaluate the critical exponents of the magnetic phase transitions. Their values are in good agreement with those obtained from the critical exponents using a modified Arrott method.