Diluted random fields in mixed cyanide crystals
Laboratoire des Milieux Désordonnés et Hétérogènes,
Université Paris 6,
Tour 13 - Case 86, 4 place Jussieu, 75252 Paris Cedex 05, France
Accepted: 7 February 1997
A percolation argument and a dilute compressible random field Ising model are used to present a simple model for mixed cyanide crystals. The model reproduces quantitatively several features of the phase diagrams although some crude approximations are made. In particu lar, critical thresholds xc at which ferroelastic first-order transitions disappear, are calculated. Moreover, transitions are found to remain first order down to xc for all mixtures except for bromine, for which the transition becomes continuous. All the results are in full agreement with experimental data.
PACS: 64.60.Ak – Renormalization-group, fractal, and percolation studies of phase transitions / 64.60.Cn – Order-disorder transformations; statistical mechanics of model systems / 64.70.Pf – Glass transitions
© EDP Sciences, 1997