Study of the special point in the surface phase diagram of a semi-infinite Ising ferromagnet

摘要

The phase diagrams of the semi-infinite Ising ferromagnet with decorated magnetic (spin-S) and nonmagnetic atoms on the surface are investigated within the framework of the effective-field theory. In particular, the critical properties of the special point in the surface phase diagram are examined numerically by changing the coupling constants, the single-ion anisotropy constant D on the spin-S (S>1/2) atom, the value of S and the concentration p of magnetic atoms. We find many characteristic features in the behaviour, such as the phenomenon depending on whether S is a half-integer or an integer. (C) 1998 Elsevier Science B.V. All rights reserved. PACS: 75.30.T; 75.10.H. [References: 13]