Range of magnetic order in Zr(Fe1-xCox)y(0⩽x⩽1, 1.8⩽y⩽2.1)

Abstract

The bulk magnetic properties as well as the ⁵⁷Fe hyperfine parameters of the pseudobinary compounds Zr(Fe_1-xCo_x)₂ were studied in the whole concentration range with the stoichiometry sometimes deviating from 2. A transition from ferromagnetism to paramagnetism is observed in this system at a certain critical concentration which sensitively depends on stoichiometry and on the sample preparation: in the concentration range 0.5<x<0.75 cluster-glass behavior as well as long-range magnetic ordering can be obtained. In a certain temperature concentration range in the presence of local moments was observed. In the region 0.5<xor=0.77 not even short-range magnetic order (visible as magnetic hyperfine splitting in a Mossbauer spectrum could be detected at T=4.2K. The discrepancies in the results published by different authors could be due to the effect of heat treatment. The magnetic phase diagram proposed by Muraoka et al. (1979, 1980) is modified.