Structure determination and crystal chemistry of large repeat mixed-layer hexaferrites


Delacotte, C, Whitehead, GFS, Pitcher, MJ ORCID: 0000-0003-2044-6774, Robertson, CM ORCID: 0000-0002-4789-7607, Sharp, PM, Dyer, MS ORCID: 0000-0002-4923-3003, Alaria, J ORCID: 0000-0001-5868-0318, Claridge, JB ORCID: 0000-0003-4849-6714, Darling, GR ORCID: 0000-0001-9329-9993, Allan, DR et al (show 2 more authors) (2018) Structure determination and crystal chemistry of large repeat mixed-layer hexaferrites. IUCRJ, 5 (Pt 6). pp. 681-698.

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Abstract

Hexaferrites are an important class of magnetic oxides with applications in data storage and electronics. Their crystal structures are highly modular, consisting of Fe- or Ba-rich close-packed blocks that can be stacked in different sequences to form a multitude of unique structures, producing large anisotropic unit cells with lattice parameters typically >100 Å along the stacking axis. This has limited atomic-resolution structure solutions to relatively simple examples such as Ba<sub>2</sub>Zn<sub>2</sub>Fe<sub>12</sub>O<sub>22</sub>, whilst longer stacking sequences have been modelled only in terms of block sequences, with no refinement of individual atomic coordinates or occupancies. This paper describes the growth of a series of complex hexaferrite crystals, their atomic-level structure solution by high-resolution synchrotron X-ray diffraction, electron diffraction and imaging methods, and their physical characterization by magnetometry. The structures include a new hexaferrite stacking sequence, with the longest lattice parameter of any hexaferrite with a fully determined structure.

Item Type: Article
Uncontrolled Keywords: large repeat hexaferrites, mixed-layer structural models, polytypes, stacking sequences, defects, magnetic properties
Depositing User: Symplectic Admin
Date Deposited: 18 Sep 2018 15:21
Last Modified: 19 Jan 2023 01:17
DOI: 10.1107/S2052252518011351
Open Access URL: https://doi.org/10.1107/S2052252518011351
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3026450
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