Issue 19, 2007

High temperature orbital order melting in KCrF3 perovskite

Abstract

The effect of high temperatures on the structural properties of the ternary transition metal fluoride KCrF3 has been investigated by high-resolution synchrotron X-ray powder diffraction. The tetragonal room temperature structure (a>c/√2) exhibits large cooperative Jahn–Teller distortions of the CrF6 octahedra which are driven by the antiferrodistortive orbital ordering of the 3d3x2−r2 and 3d3y2−r2 orbitals in the ab plane. At TJT ≈ 973 K, KCrF3 undergoes a first-order structural phase transition to an orbitally disordered cubic phase comprising equivalent Cr–F bond lengths and regular CrF6 octahedra. The onset of the orbitally disordered state is accompanied by an abrupt volume collapse, δV/V = 0.44%, which arises from the more efficient packing of the CrF6 octahedra in the orbital liquid state.

Graphical abstract: High temperature orbital order melting in KCrF3 perovskite

Supplementary files

Article information

Article type
Paper
Submitted
11 Jan 2007
Accepted
09 Feb 2007
First published
05 Mar 2007

J. Mater. Chem., 2007,17, 2013-2020

High temperature orbital order melting in KCrF3 perovskite

S. Margadonna and G. Karotsis, J. Mater. Chem., 2007, 17, 2013 DOI: 10.1039/B700487G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements