Phase diagram effects of a diluted surface on a disordered Ising film

The effects of an amorphized film and a diluted surface on the phase diagra ms and magnetic properties of a spin-in Ising film are investigated within a finite cluster approximation. Depending on the value of the concentration p of the dilution couplings at the surface, we found that there exists a c ritical value p(c); when the thickness of the film is increased the critica l temperature T-c decreases for p greater than p(c), while it increases for p less than p(c). Moreover, the critical concentration depends on the amor phization delta. Indeed, p(c) increases with increasing delta. Also, the ph ase diagram represented in (T-c, alpha), where alpha represents the strengt h of the strong coupling at the surface, shows that there exists a critical value of the amorphization delta(c) = delta(c)(p) for p not equal 1; for d elta < delta(c)(p) long range order occurs for any value of alpha at low te mperature, while for delta > delta(c)(p) an order-disorder transition occur s at T = 0 and alpha = alpha(c)(delta). The magnetization is calculated as a function of the amorphization delta, the concentration p and the strength alpha of the strong coupling.