Magnetic properties of the surface in a semi-infinite decorated Ising system with a random field at a decorated site are investigated by the effective-field theory. In particular, the phase diagram and magnetization curves for the bulk and surface of the simple cubic ferromagnetic (or...

We investigate the critical properties of a mixed spin-1/2 and spin-S(S1/2) transverse Ising model, changing the value of S. In this study, the new type of cluster theory is introduced on the basis of the differential operator technique and Ising spin identities. It is found that the theory...

The specific heat and temperature dependence of magnetizations in transverse Ising thin films are investigated by the use of the standard mean-field theory and the effective-field theory with correlations. The exchange interaction and transverse field at the surfaces take values different from...

Transition temperatures of a bilayer system with A2 (ApB1−p)1 (B)2 consisting periodically of two layers of spin-12 A atoms, two layers of spin-32 B atoms and an interface with alloying-type (ApB1−p) disorder are examined by the use of the effective-field theory superior to the standard...