Crystal field in nitrogenated rare-earth intermetallics

Authors

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

Document Type

Article

Date of this Version

May 1993

Comments

Published by Am Inst of Physics. J. Appl. Phys. 73 (1993) 6934-6936. Copyright 1993. Permission to use. http://www.aip.org/.

Abstract

The crystal-field in Sm₂Fe₁₇N_{3- δ} and Sm(Fe₁₁Ti)N_{1- δ} due to interstitial nitrogen has been investigated. Intrinsic parametrization in the superposition model allows separation of the crystal field created by a neighboring nitrogen atom from a purely geometrical factor, which is different for Sm₂Fe₁₇N_{3- δ} and Sm( Fe₁₁Ti) N_{1- δ} Using published magnetic data, values for the intrinsic parameter A₂ per nitrogen atom of A₂=200± 60 Ka₀^-2 and A₂=270±60 Ka₀^-2 for Sm₂Fe₁₇N_{3- δ} and Sm(Fe₁₁Ti)N_{1- δ}, respectively, are obtained. Because of charge penetration, which is discussed in the form of an explicit crystal-field weight function, it is not possible to interpret A₂⁰ or à ₂ as crystal-field parameters independent of the 4f ion.