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

DOI: 10.1107/S2052252518011351

Authors: C. Delacotte (University of Liverpool) , G. F. S. Whitehead (University of Liverpool) , M. J. Pitcher (University of Liverpool) , C. M Robertson (University of Liverpool) , P. M. Sharp (University of Liverpool) , M. S. Dyer (University of Liverpool) , Jo. Alaria (University of Liverpool) , J. B. Claridge (University of Liverpool) , G. R. Darling (University of Liverpool) , D. R. Allan (Diamond Light Source) , G. Winter (Diamond Light Source) , M. J. Rosseinsky (University of Liverpool)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Iucrj , VOL 5

State: Published (Approved)
Published: November 2018
Diamond Proposal Number(s): 15777

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 Ba2Zn2Fe12O22, 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.

Journal Keywords: large repeat hexaferrites; mixed-layer structural models; polytypes; stacking sequences; defects; magnetic properties

Diamond Keywords: Data Storage

Subject Areas: Materials, Chemistry, Physics


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 13/09/2018 11:39

Documents:
lt5011.pdf

Discipline Tags:

Physics Physical Chemistry Components & Micro-systems Information & Communication Technologies Chemistry Magnetism Materials Science Inorganic Chemistry

Technical Tags:

Diffraction Single Crystal X-ray Diffraction (SXRD)