Arrott plots, M 4 plots and the critical temperature of the weak ferromagnet FeGa3-yGey

Abstract

The Curie temperature TC of the weakly ferromagnetic system FeGa3-yGey is investigated by means of isothermal magnetization experiments. The critical temperature of the ferromagnetic phase transition is estimated by the so-called M4 plots rather than the Arrott plots technique. The M4 plots are exploited from the sixth power term of the expanded free energy, which is neglected by the Arrott plots. The magnetic properties are analyzed by taking into account the effects of spin fluctuations in terms of related spin-fluctuation theories.