Magnetic properties of a diluted transverse spin-1/2 Ising film

The layer longitudinal magnetizations, their average, and both the longitud inal and the transverse susceptibilities of a diluted transverse spin-1/2 I sing film are studied within the framework of the effective field theory. T he results show that the surface layer longitudinal magnetization can be sm aller or larger than the internal layer longitudinal magnetization, dependi ng on the values of the ratio of the surface exchange interactions to the b ulk ones R = J(s)/J, the concentration c of the magnetic atoms and the temp erature T/J. It is also shown that the longitudinal susceptibility diverges at the critical temperature T-c/J while the transverse susceptibility disp lays a cusp at the critical temperature. (C) 1999 Published by Elsevier Sci ence B.V. All rights reserved.