UNIVERSALITY OF SURFACE CORRELATION-FUNCTIONS IN 3-DIMENSIONAL MODELS

Universality of surface critical behavior with respect to surface enha ncement is studied for O(n) models with n = 1 (Ising), n = 2 (planar r otor), and n = 3 (Heisenberg) on simple-cubic lattices. Finite-size me thods are employed to estimate surface critical exponents for ordinary surface criticality. In addition, it is shown that universal scaling functions, independent of surface enhancement, can be constructed with all nonuniversal features of the finite-size scaling function of the spin-spin surface correlation functions incorporated in (1) a metric f actor and (2) an irrelevant scaling field associated with the surface coupling strength.