Structural Chemistry and Spin-Glass Behaviour of Nd₁₈Li₈Fe₄TiO₃₉

Abstract

Nd18Li8Fe4TiO39 has been synthesised and characterised by neutron powder diffraction, X-ray absorption spectroscopy, Mössbauer spectroscopy and magnetometry. The cubic structure (Pm3n, a=11.97227(8) Å) is based on intersecting < 1 1 1 > chains comprised of alternating octahedral and trigonal-prismatic coordination sites. These chains lie within hexagonal-prismatic cavities formed by a NdO framework. The larger of the two crystallographically distinct octahedral sites, 8e, is occupied by iron, titanium and lithium in a ratio of 76:20:4; the smaller, 2a, is occupied by iron and titanium in a ratio of 79:21. The trigonal-prismatic site, 16i, is occupied by lithium and iron in a ratio of 98:2. The cations on the 2a sites are assigned as Ti 4and low-spin Fe 4, and those on the 16i sites as Li and Fe 3. The 8e sites are thought to be occupied by Li, Fe 3 and Ti 3. Nd 18Li 8Fe 4TiO 39 undergoes a transition to a spin-glass state at 4.25(5) K

Department(s)

Chemistry

Keywords and Phrases

Coordination Sites; Cubic Structure; Octahedral Sites; Spin-glass State; Ssbauer Spectroscopies; Structural Chemistry; TiO; XANES; Iron; Metallic Compounds; Neodymium; Spin Glass; Titanium; X Ray Absorption Spectroscopy; Lithium; Mixed-metal Oxide; Spin Glass; XANES

International Standard Serial Number (ISSN)

0022-4596

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2012 Elsevier, All rights reserved.

Publication Date

01 Mar 2012

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