Computer simulation of domain structures in spin/strain systems

Abstract

Large scale computer simulations of spin systems with strong coupling between the spin degrees of freedom and the lattice strain show the following characteristic features:

Comparison with experimental studies show similar behaviour in Co,Fe doped YBCO, cordierite and Na-feldspar.

1.	the order parameter follows mean field behaviour (Marais et al, 1991) with converging Levanyuk integrals.
2.	Domain formation (kinks and tweed) dominates over cluster nucleation and growth (Salje 1990, Salje and Parlinski,1991).
3.	Kinetic texture is always tweed-like for the early stages. Tweed coarsening occurs at temperatures close to Tc whereas tweed transforms to stripes at lower temperatures (Parlinski et al. 1992a).