Analysis of the Magnetization as a Function of the Magnetic Field at the Transition Temperature for La0.6nd0.4mn2si2

Abstract

We analyze in this study our experimental data for the magnetization (M) as a function of the magnetic field (H) at various constant temperatures for the multilayer structure of La Nd-0.6 Mn-0.4 Si-2 (2) close to the ferromagnetic-antiferromagnetic transitions. This analysis is performed at the transition temperatures (T (c)) for the M vs. H- H (c) (H (c) is the critical field) according to a power-law formula above and below H (c), and the values of the critical isotherm delta are deduced for La Nd-0.6 Mn-0.4 Si-2 (2). We also calculate the magnetic field (H- H (c)) dependence of the isothermal susceptibility chi (T) at constant temperatures above and below H (c), and we obtain the critical behaviour of chi (T) for this multilayer structure. Our delta values indicate that the ferromagnetic-antiferromagnetic transition in La Nd-0.6 Mn-0.4 Si-2 (2) changes its character from a first order (discontinuous) toward a second-order (continuous) one as the constant temperature changes.