Enhancement of the Magnetic Properties of Sm-Fe and Nd-Fe-N Alloys with ThMn₁₂ Structure by Utilizing HDDR Phenomena

Abstract

The effects of the HDDR (hydrogenation decomposition desorption recombination) phenomenon on the magnetic properties of SmFe₁₁Ti, SmFe₁₀MM′, NdFe₁₁Ti, and Nd_1+δFe₁₀MM′ (δ=0, 0.3, M=Ti, V, Mo, M′=V, Mo) compounds with ThMn₁₂-type Structure were investigated. Alloy powders of SmFe₁₀V₂, SmFe₁₀TiV, and NdFe₁₀MM′; (M=Ti, V, Mo, M′;=V, Mo) form a ThMn₁₂-type structure after heat treatment at 800°C in hydrogen and subsequently in a vacuum, but RFe₁₁Ti (R=Sm, Nd) compounds form a TbCu₇-type structure. High coercivities of 6.0 kOe and 5.8 kOe were obtained with SmFe₁₀TiV and Nd_1.3Fe₁₀VMoN_x compounds subjected to the HDDR Phenomena, respectively.