Issue
EPL
Volume 77, Number 5, March 2007
Article Number 56001
Number of page(s) 5
Section Condensed Matter: Structural, Mechanical and Thermal Properties
DOI http://dx.doi.org/10.1209/0295-5075/77/56001
Published online 15 February 2007
EPL, 77 (2007) 56001
DOI: 10.1209/0295-5075/77/56001

Landau theory applied to phase transitions in calcium orthotungstate and isostructural compounds

D. Errandonea

Departamento de Física Aplicada-ICMUV, Universitat de València - Edificio de Investigación, c/Dr. Moliner 50, 46100 Burjassot (Valencia), Spain

daniel.errandonea@uv.es

received 23 November 2006; accepted in final form 3 January 2007; published March 2007
published online 15 February 2007

Abstract
The pressure-driven tetragonal-to-monoclinic phase transition in ${\rm CaWO}_{4}$ and related scheelite-structured orthotungstates is analysed in terms of spontaneous strains. Based upon our previous high-pressure X-ray diffraction results and the Landau theory, it is suggested that the scheelite-to-fergusonite transition is of second order in nature.

PACS
61.50.Ks - Crystallographic aspects of phase transformations; pressure effects.
62.50.+p - High-pressure and shock wave effects in solids and liquids.
64.70.Kb - Solid-solid transitions.

© Europhysics Letters Association 2007