A structural, magnetostrictive and Mössbauer study of Tb0.3Dy0.7(Fe0.9T0.1)1.95 alloys

Abstract

The effect of ⅢA metal and transition metal T substitution for Fe on crystal structure, magnetostriction and spontaneous magnetostriction, anisotropy and spin reorientation of a series of polycrystalline Tb 0.3 Dy 0.7 (Fe 0.9 T 0.1 ) 1.95 ( T = Mn, Fe, Co, B, Al, Ga) alloys at room temperature were investigated systematically. It was found that the primary phase of the Tb 0.3 Dy 0.7 (Fe 0.9 T 0.1 ) 1.95 alloys is the MgCu 2 -type cubic Laves phase structure for different substitution. The magnetostriction λ s decrases greatly for the substitution of IIIA metal B, Al and Ga, but is saturated more easily for Al and Ga substitution, showing that the Al and Ga substitution is beneficial to a decrease in the magnetocrystalline anisotropy of Tb 0.3 Dy 0.7 (Fe 0.9 T 0.1 ) 1.95 alloys. However, the substitution of transition metal Mn and Co decreases slightly the magnetostriction λ s . It was also found that the effect of different substitutions on the spontaneous magnetostriction l111 is distinct. The analysis of the Mossbauer spectra indicates that the easy magnetization direction in the {110} plane deviates slightly from the main axis of symmetry for Al and Ga substitution, namely spin reorientation, but it does not change evidently for B, Mn and Co substitution.