New Magnets from Interstitial Intermetallics

Authors

J.M.D. Coey, Trinity College, Dublin, Ireland
Ralph Skomski, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

April 1993

Comments

Published in Physica Scripta. Vol. T49, 315-321, 1993.

Abstract

The outlook for improving the energy product of permanent magnets beyond the theoretical limit of 516 kJ/m³ for Nd₂Fe₁₄B is discussed. Most promising are nanostructured two-phase magnets consisting of an aligned hard-magnetic skeleton phase possessing exceptionally high uniaxial anisotropy and a soft-magnetic phase which assures a high magnetization. Brown’s paradox is discussed for inhomogeneous magnets, and micromagnetic calculations are used to predict energy products as high as 1090 kJ/m3 in suitable nanostructured Sm₂Fe₁₇N₃/Fe₆₅Co₃₅ composites, such as multilayers or disordered two-phase magnets with common c axis.