Martensitic textures: Multiscale consequences of elastic compatibility

We show that a foe energy entirely in the order-parameter strain variable(s ), rather than the displacement field, provides a unified understanding of martensitic textures. We use compatibility equations, linking the strain te nsor components in the bulk and at interfaces, that induce anisotropic orde r-parameter strain interactions. These two long-range bulk/interface potent ials, together with local compositional fluctuations, drive the formation o f global elastic textures. Relaxational simulations show the spontaneous fo rmation (and evolution under stress/temperature quenches) of equal width pa rallel twins, branched twins, and tweed, including characteristic scaling o f twin width with twin length. [S0163-1829(99)51442-2].