Magnetic Properties of the Intermetallic Compounds DyxY1−xFe2

Abstract

Measurements of the bulk magnetization have been made between 4.2°K and the Curie points for eleven compounds in the series Dy_xY_1−xFe₂. The Curie temperatures increase continuously through the series. The compounds near to x=0.3–0.4 exhibit temperature compensation points, and the saturation moments show that the equilibrium concentration occurs at x≃0.28. In addition, the coercivity increases rapidly in this region and has a value in excess of 10 kOe at x=0.35, T=4.2°K. If both the Fe and Dy moments remain constant or vary linearly through the series, the equilibrium concentration would occur at x≃0.35. Consideration of the results of these and other similar compounds indicates that the Fe moment varies nonlinearly with x. It is suggested that the Fe moment is approximately 1.4 μ_B for x<⅓ and increases gradually for larger x to about 2 μ_B. It is further proposed that this behavior may be explained by the presence of a shallow minimum in the density‐of‐states curve, sufficient to stabilize the moment for x<⅓, but such that the increased coupling allows the moment to increase for higher Dy concentrations. The Fe moments in other RE Fe₂ compounds are correlated with this model, taking the Curie temperatures as a measure of the exchange energies.