Weak itinerant magnetic behaviour in Al substituted Ni 92 Cr 8 alloys

Abstract

In the present work we report low temperature magnetic properties of Ni92−xAlxCr8 alloys. It is found that the Curie temperature and spontaneous magnetization (MSP) get suppressed around xC ≈ 7. From the analysis of the temperature and field dependent magnetization data we have obtained high value of Rhodes–Wohlfarth ratio, which indicates the weak itinerant ferromagnetic behavior for samples below xC. This is further supported by analysing the temperature variation of MSP in the framework of spin fluctuations, SCR theory. Furthermore, the Ginzburg-Landau formalism-based on spin fluctuation theory revealed that the contribution of spin fluctuations at low temperature increases as we approach xC.