Effective field theory study of bond dilution effects on transverse Ising antiferromagnet in a random longitudinal magnetic field

The transverse antiferromagnetic spin-12 Ising model is studied within the effective field theory with correlations for a finite cluster with random bond dilution and random longitudinal magnetic field effects. The bonds are either randomly antiferromagnetically switched on with probability p or switched off with 1−p. In addition, the external magnetic field is randomly turned up or down in the longitudinal direction with probability t and 1−t, respectively. The thermal variations of the longitudinal and transverse sublattice magnetizations, as well as the staggered longitudinal magnetizations with coordination numbers q=4 and 6, are studied to obtain the phase diagrams of the model. It is found that the model exhibits both first- and second-order phase transitions. Compensation temperatures and reentrant behaviors are also shown for appropriate values of the system parameters.