Proceedings of the Ninth Conference on the Silicate Industry, Budapest, 1976: Edited by F. Tamás. 1968. Publishing House of the Hungarian Academy of Sciences, Budapest. 756 pp. illus. $24

Abstract

In this actual work, we have already studied the universal critical behavior in perovskite-manganite compound Nd0.6Sr0.3Ca0.1Mn0.975Fe0.025O3. An approve of a second order ferromagnetic-paramagnetic phase transition through the magnetic measurements using Banerjee's criteria is completely clarified. The critical exponents values near the critical point TC are determined through several techniques such as modified Arrott plot (MAP), Kouvel Fisher (KF) method and critical isotherm (CI). The critical exponents values obtained agree toughly with the mean field model (β = 0.478 ± 0.01 with TC = 232 K ± 0.9 K and γ = 1.039 ± 0.02 with TC = 230 K ± 0.94 K). We have confirmed the obtained critical exponents with the single scaling equation of: M(H,ε)=εβf±(H/ε(β+γ)) With ε = (T−TC)/TC is the reduced temperature.We have verified the agreement between two different methodologies of determining the spontaneous magnetization (MS) in Nd0.6Sr0.3Ca0.1Mn0.975Fe0.025O3 manganite. Used the spontaneous magnetization (MS) obtained through the magnetic entropy change (ΔSM) vs M2; we have fitted MS(T) curves to obtain an excellent agreement between the theoretical and experimental value of β. This result leads to confirm the validity of the magnetic entropy change approach in order to estimate the spontaneous magnetization MS in a ferromagnetic system.