Effect of Gd substitution on the critical scaling of the ferromagnetic transition of La0.6-x Gdx Sr0.4 MnO3(x=0, 0.05, 0.1) manganite

This paper presents a detailed study on the critical properties of perovskite manganite La0.6-x Gdx Sr0.4 MnO3(x = 0, 0.05, 0.1) synthesized by Sol-gel method. The critical exponents near the PM-FM phase transition are determined through various methods such as modified Arrot plot, Kouvel-Fisher methods, and critical isothermal analysis based on the data of magnetic measurements recorded around the Curie temperature. These specimens are in agreement with their corresponding values proved by Widom scaling law, as well as the scaling theory. According to the values of critical exponents, the presence of the phase transition is found to be not relevant to the common transition classes but they can be attributed to some abnormal variations. It is suggested that the induced lattice disordering and magnetic disordering, as a result of Gadolinium incorporation, to be potential reasons for the presence of a large magnetocaloric effect, in addition to an anomalous ferromagnetic phase transition in the studied material.