Critical behavior of polycrystalline Pr0.7Ca0.1Sr0.2MnO3 exhibiting the crossover of first and second order magnetic phase transitions

Abstract

A polycrystalline ceramic of Pr0.7Ca0.1Sr0.2MnO3 was prosperously synthesized by the solid state reaction method. The M(T, H) data measured at different temperatures in applied magnetic fields H = 0-30 kOe showed that the material has a ferromagnetic-paramagnetic phase transition and exhibits the crossover of the first and second order magnetic phase transitions. Above Curie temperature (T-C), the chi(-1)(T) curve witnesses a downturn in the paramagnetic region, suggesting an appearance of the Griffiths phase. Using the modified Arrott plots and the Kouvel-Fisher methods, we have identified a set of the critical parameters (T-C, beta, gamma, and delta) for Pr0.7Ca0.1Sr0.2MnO3 compound. The results are found to be T-C = 205.5 + 0.1 K, beta = 0.191 + 0.010, gamma = 0.856 + 0.016 and delta = 5.649 + 0.030. It can be seen that the values of the exponents beta, gamma, and delta are quite close to the exponents of the tricritical mean field model. Additionally, they satisfy the scaling theory well, proving their reliability. Based on obtained results, we suggest that the ferromagnetic-paramagnetic transition in Pr0.7Ca0.1Sr0.2MnO3 compound is located at a crossover of the first and second order transformations. (C) 2020 The Author(s). Published by Elsevier B.V.