title: A unified description of the double perovskite family Sr2MWO6within a rigid ion model.
abstract: The sequence of phase transitions and structural instabilities of the Sr2MWO6double perovskites are investigated using a rigid ion model. The parametrization of the short range empirical potential allows the control of the cation sizes by means of independent parameters, and in particular, the effective size of the M cation can be tuned to reproduce the behaviour of the whole family. The coupling of symmetry modes and its role in the stability of the phases are discussed, and molecular dynamics simulations are carried out to determine structural phase transitions as a function of temperature. A satisfactory agreement between experiments and ab initio calculations is obtained for the relevant range of ionic radii and temperatures, indicating that the range of stability of the structures is mainly governed by steric effects.
authors.affiliation: Fisika Aplikatua II Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, P.K. 644, 48080 Bilbao, Spain. inigo.etxebarria@ehu.eus.
authors.forename: Urko
authors.initials: U
authors.lastname: Petralanda
authors.affiliation: Fisika Aplikatua II Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, P.K. 644, 48080 Bilbao, Spain. inigo.etxebarria@ehu.eus.
authors.forename: I
authors.initials: I
authors.lastname: Etxebarria