Critical field analysis of modified arrott plots (MAP) in MnCoGe0.97Al0.03alloy

MnCoGe system has attracted extensive attention since the find of the field-induced martensitic transition. To better understand the intrinsic nature of the interactions and magnetism in this material, it is essential to study further the order and nature of the FM-PM magnetic transition. This paper discussed the critical properties of MnCoGe0.97Al0.03 alloy around the FM-PM magnetic transition investigated through modified Arrott plots (MAP) analysis. Data obtained near TC were examined in the framework of the mean-field theory, the 3D-Heisenberg model, the 3D-Ising model, and the tricritical mean-field. The deduced critical exponents values obtained using the MAP method were β = 0.429 and γ= 0.80 with TC = 348 K. The obtained critical parameters show a tendency towards the mean-field behavior, suggesting the existence of long-range ferromagnetic order in the compound studied.