Critical behavior and magnetic entropy change in Nd0.7Sr0.1Ba0.1Ca0.1MnO3−δ perovskite manganite

Abstract The aim of our study was to investigate the critical exponents of Nd 0.7 Sr 0.1 Ba 0.1 Ca 0.1 MnO 3− δ material around its paramagnetic to ferromagnetic phase transition. Reliable critical exponents i.e. β =0.355, γ =1.329, and δ =4.867 at the critical temperature T C =117 K were refined using modified Arrott plot and Kouvel–Fisher methods. The critical exponent δ =4.760±0.129 was further separately determined from the isothermal magnetization data. Finally these critical exponents fulfill the Widom scaling relation δ =1+ γ / β . Based on these analysis, the magnetization–field–temperature ( M – H – T ) data around T C collapses into two independent curves obeying the single scaling equation M(H , e )=| e | β f ± ( H /| e | β + γ ), with e =( T − T C )/ T C is the reduced temperature. Once again, the critical exponents are confirmed by the field dependence of the magnetic entropy change relation ∆ S M | T = T C ∞ H n with n =1+( β− 1)/( β +1). The obtained critical exponents for Nd 0.7 Sr 0.1 Ba 0.1 Ca 0.1 MnO 3− δ manganite are in accordance with the prediction of the 3D-Heisenberg model with short-range magnetic interactions. The temperature dependence of specific heat and magnetic entropy change Δ S M further supports second order PM–FM phase transition and shed light the A-site-disordered perovskite effect on the magnetocaloric properties.