Accession Number : ADA111815

Title :   Phase Diagram of Ising Models with Random Sublattice Vacancies.

Descriptive Note : Technical rept.,

Corporate Author : MAINE UNIV ORONO DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Hu,Chin-Kun ; Kleban,Peter

PDF Url : ADA111815

Report Date : Feb 1982

Pagination or Media Count : 14

Abstract : We use a modified Kadanoff's variational method to calculate the phase diagram of an Ising model with random vacancies on one of two interpenetrating sublattices of the isotropic square (SQ) and body-centered cubic (BCC) lattices. We find second order phase transitions only for T0. The transition temperature to very good approximation decreases linearly with impurity (i.e. vacancy) concentration at small concentration. This agrees with the linear decrease observed in other systems. A plausible explanation of the absence of first order transitions for T0 is given. The relation of our models to certain percolation problems is similar to that of some spin models studied by Syozi. Thus our results allow an estimate of critical probabilities for percolation. (Author)

Descriptors :   *Phase transformations, *Crystal structure, Vacancies(Crystal defects), Transition temperature, Isotropism, Percolation, Impurities, Phase diagrams, Computations, Variational methods, Crystal lattices

Subject Categories : Crystallography
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE