Critical behavior near the paramagnetic to ferromagnetic phase transition temperature in La0.7Ca0.2Sr0.1Mn1−xCrxO3 compounds (0 < x < 0.1)

Abstract

The critical behavior of the La0.7Ca0.2Sr0.1Mn1−xCrxO3 (0<x<0.1) was carried out by measurement of the magnetization around the Curie temperature TC. Experimental results revealed that these samples exhibit a second-order magnetic phase transition. The critical properties are investigated through various techniques such as modified Arrott plot, Kouvel–Fisher methods and critical isotherm to analyze magnetic-field dependences of magnetization. The values of critical exponents which are derived from the magnetic data, using the above methods, yield 0.24⩽β⩽0.25 and 1.01⩽γ⩽1.08 with TC in the range of 255–294K. The critical isotherm M(TC, H) gives δ=4.9±0.1. Thus, the scaling law γ+β=δβ is fulfilled. The critical exponents obey the single scaling equation of state Mμ0H,ε=εβf±μ0H/εβ+γ, where f+ for T>TC and f− for T<TC. The estimated critical exponents are close to the tricritical mean field model for the Cr doped sample suggesting short-range interaction.