Phase diagrams of the site-diluted spin-1/2 Ising film in a transverse field

Within the framework of the effective field theory, with a probability dist ribution technique that accounts for the single-site spin correlations, we examine the critical behavior of a diluted spin-1/2 Ising film. The critica l temperature of the system is studied as a function of the thickness of th e film, the concentration of magnetic atoms, the strength of the transverse field and the couplings. It is shown that for the ratio of the surface cou plings to the bulk ones R = J(s)/J less than a critical value R-c, the crit ical temperature of the film T-c/J is smaller than the bulk critical temper ature T-c(B)/J and for R greater than or equal to R-c, T-c/J is larger than the bulk critical temperature T-c(B)/J and T-c(S)/J of the corresponding s emi-infinite system. As the film thickness L is increased further T-c/J inc reases for R less than or equal to R-c (decreases for R greater than or equ al to R-c) and approaches asymptotically for large values of L the bulk cri tical temperature T-c(B)/J (the surface critical temperature T-c(S)/J) of t he corresponding semi-infinite system.