Electrical and magnetic properties of amorphous Fe22.5Co22.5Ni22.5Cr22.5Zr10 alloy

Abstract

This report is focused on the investigation of electrical and magnetic properties of distorted bcc system. The inspiration for the selection of amorphous Fe22.5Co22.5Ni22.5Cr22.5Zr10 alloy with a distorted bcc structure is based on the theoretical band calculation. It is confirmed that the free electron density of state of disordered bcc FeNiCr alloy increases at Fermi surface.Amorphous Fe22.5Co22.5Ni22.5Cr22.5Zr10 alloy, hereafter denoted as a-FeCoNiCrZr, shows among all the metallic materials the weakest temperature dependence of the electrical resistivity, ρ0(T). The weak ρ0(T) has been interpreted in the context of different physical processes such as tunnelling of free electrons and electron phonon interactions.Magnetically, a-FeCoNiCrZr consists of independent soft ferromagnetic clusters with average cluster size of about 1840 atoms. The Curie temperature, TC, was verified using Landau’s theory of second-order phase transitions in low non-zero external fields. The reduced magnetization, M(T)/M(0), as a function of reduced temperature, T/TC, is explained in the framework of the exchange integral fluctuation theory. The exchange integral fluctuation is dominant only at low external fields. At Bex = 9 T, the exchange integral fluctuation has no noticeable effect on reduced magnetization. At Bex = 9 T, the precision of magnetic clusters around the Bex controls the behaviour of reduced magnetization as function of temperature.