Continuous Versus First Order Transitions in Compressible Diluted Magnets
arXiv:cond-mat/9606121 · doi:10.1016/0378-4371(95)00381-9
Abstract
The interplay between disorder and compressibility in Ising magnets is studied. Contrary to pure systems in which a weak compressibility drives the transition first order, we find from a renormalization group analysis that it has no effect on disordered systems which keep undergoing continuous transition with rigid random-bond Ising model critical exponents. The mean field calculation exhibits a dilution-dependent tricritical point beyond which, at stronger compressibility the transition is first order. The different behavior of XY and Heisenberg magnets is discussed.
16 pages, latex, 2 figures not included