Synthesis, structure and properties of the oxychalcogenide series A4O4TiSe4 (A=Sm, Gd, Tb, Dy, Ho, Er and Y)

Tuxworth, A.J.; Evans, J.S.O.

doi:10.1016/j.jssc.2013.11.006

Synthesis, structure and properties of the oxychalcogenide series A4O4TiSe4 (A=Sm, Gd, Tb, Dy, Ho, Er and Y)

Tuxworth, A.J.; Evans, J.S.O.

Authors

A.J. Tuxworth

Professor John Evans john.evans@durham.ac.uk
Professor

Abstract

Seven oxyselenide materials have been synthesised with composition A4O4TiSe4 (A=Sm, Gd–Er, Y) via solid state reactions of A2O3, TiSe2 and Se at 900 °C. They are all isostructural with Gd4O4TiSe4. Structures have been refined from powder X-ray diffraction data and have monoclinic C2/m symmetry with unit cell parameters of a≈15.7 Å, b≈3.75 Å, c≈9.65 Å and β≈117.5°. They contain infinite ribbons of edge-sharing A4O and A3TiO tetrahedra 4 units wide, which are linked by chains of TiSe4O2 edge-sharing octahedra. Compositions A=Gd–Ho, Y are semiconductors with conductivities 1–3 Sm−1 at 300 K, with electronic band gaps of between 0.25 and 0.37 eV. Magnetic susceptibility is reported from 1.8 K to 300 K for compositions A=Gd–Ho. Rare earth moments appear to order antiferromagnetically at low temperatures with Gd and Tb showing evidence of ferromagnetism due to spin canting over a narrow temperature range close to TN.

Citation

Tuxworth, A., & Evans, J. (2014). Synthesis, structure and properties of the oxychalcogenide series A4O4TiSe4 (A=Sm, Gd, Tb, Dy, Ho, Er and Y). Journal of Solid State Chemistry, 210(1), 188-194. https://doi.org/10.1016/j.jssc.2013.11.006

Journal Article Type	Article
Acceptance Date	Nov 2, 2013
Online Publication Date	Nov 21, 2013
Publication Date	Feb 1, 2014
Deposit Date	May 4, 2015
Publicly Available Date	Feb 13, 2018
Journal	Journal of Solid State Chemistry
Print ISSN	0022-4596
Electronic ISSN	1095-726X
Publisher	Elsevier
Peer Reviewed	Peer Reviewed
Volume	210
Issue	1
Pages	188-194
DOI	https://doi.org/10.1016/j.jssc.2013.11.006