Phase diagrams and tricritical behavior in a spin- Ising model with transverse crystal field

Within the framework of the effective-field theory with correlations, the ferromagnetism of spin- Ising model with a transverse crystal field on honeycomb and square and simple cubic lattices is studied. Tricritical phenomena have been observed for the square and simple cubic lattices, but there is no tricritical point for the honeycomb lattice. We have investigated the effect of the transverse crystal field on the phase diagrams, magnetization, quadrupolar moments, internal energy, and specific heat of the system on the square lattice in detail.