A structural and magnetic study of Nd5Fe2B6 and Nd5Fe2B6D4.1

JOURNAL OF ALLOYS AND COMPOUNDS

卷:693

Article

Tence, S.^1,2,3,4  Wattiaux, A.^1,2  Duttine, M.^1,2  Decourt, R.^1,2  Isnard, O.^3,4 

[1] CNRS, ICMCB, UPR 9048, F-33600 Pessac, France

[2] Univ Bordeaux, ICMCB, UPR 9048, F-33600 Pessac, France

[3] Univ Grenoble Alpes, Inst NEEL, F-38042 Grenoble, France

[4] CNRS, Inst NEEL, F-38042 Grenoble, France

关键词: Boron hydride;    Hydrogenation;    Magnetic measurements;    Fe-57 Mossbauer spectroscopy;    Neutron diffraction;    Magnetic structure;   

DOI  :  10.1016/j.jallcom.2016.09.243

来源: Elsevier

【 摘 要 】

We investigated the structural and magnetic properties of the boride Nd5Fe2B6 and of the deuteride Nd5Fe2B6D4.1 by means of magnetization and specific heat measurements, Mossbauer spectroscopy and neutron powder diffraction. In Nd5Fe2B6D4.1, deuterium atoms are located in two inequivalent interstitial sites: one octahedral D1 [Nd6] and one tetrahedral D2 [Nd3Fe], both avoiding B as near neighbor. This insertion induces a pronounced anisotropic unit cell expansion along the c-axis. While the Nd5Fe2B6 compound exhibits a magnetic ordering below about 68 K, the deuteride exhibits a lower ordering temperature of about 21 K as a consequence of D insertion in the Nd environment. For both compounds powder neutron diffraction investigations have evidenced a ferromagnetic structure with magnetic moments along the c-axis. However, in the deuteride, the Nd magnetic moments values are reduced and that of Fe vanishes. Fe-57 Mossbauer spectroscopy confirms the existence of a small ordered magnetic moment on iron in Nd5Fe2B6 and the presence of two environments for Fe in the deuteride. (C) 2016 Elsevier B.V. All rights reserved.

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