Classical displacive limit of an n-component model for structural phase transitions

The static critical behavior of an n-component model at the displacive limit is investigated by means of classical mechanics. In the large-n limit, critical exponents and crossover behavior are found by explicit calculation, whereas renormalization-group and scaling relations are used to treat the case of general n exactly for arbitrary dimension. The exponents at the displacive limit, i.e., for Tc=0, are classical for d>2. They are independent of n and differ from those of Tc>0 for d<4. © 1975 The American Physical Society.