Magnetostriction of Co80−xTxB20 (T = Fe, Mn, Cr, or V) glasses

Abstract

Magnetostriction measurements as a function of temperature and composition are reported in non‐crystalline Co_80−xT_xB₂₀ alloys (T = Fe, Mn, Cr or V with 0⩽x⩽12 at. %). The room temperature saturation magnetostriction λ_s changes sign with the substitution of Fe, Mn or Cr for Co in Co₈₀B₂₀ glass. These results are well described by the virtual‐bound‐states (VBSs) introduced above the 3d band by the light T solutes. The positions of 3d^↑ (3d majority spin) VBS with respect to the Fermi energy is established. The magnetostrictions of Co₇₂Mn₈B₂₀ and Co₇₀Cr₁₀B₂₀ glasses (negative at 295 K) also change sign with increasing temperature. This is the first direct observation of magnetostriction‐compensation temperatures in non‐crystalline metals. The existence of these magnetostriction compensation temperatures is interpreted to be a consequence of the different temperature dependences of single‐ion and two‐ion contributions to λ_s.