THEORY OF EPITAXY AT FINITE TEMPERATURES - AN APPLICATION TO ORIENTATIONAL PHASE-TRANSFORMATIONS ON RECONSTRUCTED AU(001) SURFACES

A new finite temperature epitaxy theory has been introduced which allo ws us to study epitaxy in systems with nonadditive many-body potential s in finite temperatures. This method is applied to hexagonally recons tructed Au(001) surfaces. We find rotated domains on the surfaces with rotation angles theta approximate to 0.72 degrees, 0.86 degrees, and 1.14 degrees, depending on cluster size and shape. These rotated domai ns undergo orientational phase transformations at temperatures below t he melting temperature. We predict that the orientational phase transf ormations may be accompanied by a reconstruction pattern transformatio n.