The 1/n Expansion for the n-Vector Model in the Semi-Infinite Space

The 1/n expansion method is developed in the study of the critical behavior of the n-vector model with a free surface. The method is applied at the bulk critical temperature (T = Tc) in the absence of the surface ordering. The surface critical exponents η;// and η;⊥ are identified up to order 1/n for general spatial dimension d: 2 ≪ d ≪ 4 for the ordinary transition and 3 ≪ d ≪4 for the special transition. The results are compared with several scaling relations, other theories and some experiments.