Magnetization and ⁵⁷Fe hyperfine fields in Y₂Fe₁₇Z_{3- δ} (Z=H, C, or N) interstitial compounds

Authors

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

Date of this Version

June 1992

Comments

Published by Am Physical Soc. Phys. Rev. B 45 (1992) 12278-12286. Copyright 1992. Permission to use. http://www.aps.org/.

Abstract

Measured magnetization and ⁵⁷Fe hyperfine fields at T∼0 K for Y₂Fe₁₇ and Y₂Fe₁₇Z_{3- δ} , with Z=H, C, or N and δ∼0.5, are analyzed to determine the influence of the interstitial atoms on the 3d magnetism. All are weak ferromagnets with a nearly-full 3d subband, although when Z=N, the magnetic moment of 38.1μ_B is very close to the fully saturated value of 39.4μ_B. On a local scale, the order of hyperfine fields B_hf^4f (=35 T)> B_hf^6g (=33 T)> B_hf^12j (=30 T)> B_hf^12k (=28 T) is different from that of the local magnetic moments given by several recent band calculations for Y₂Fe₁₇, μ^4f (=2.5μ_B)>μ^12j (=2.2μ_B)>μ^12k (=2.0μ_B)>μ^6g (=1.9 μ_B), reflecting a large 4s-transferred hyperfine field at 6g sites which have very short Fe-Fe distances. The volume of samples with Z=C and N are identical, and so the chemical effects of the interstitials can be distinguished; both the local magnetic moment and hyperfine fields are systematically smaller in the carbide than the nitride by 5% and 12%, respectively.