Random Transverse Crystal-Field Effects On The Magnetic Properties Of The Spin-3/2 Blume-Capel Model

The spin-3/2 Blume-Capel (BC) model under the effect of a random transverse crystal-field (RTCF) is studied on the square lattice within the mean-field approach. The crystal-field is either turned on or off randomly on the spin sites with probability p and 1 - p, respectively. The probability p satisfies 0 <= p <= 1.0 and the magnetic bilinear interaction parameter, i.e. J > 0. The thermal variations of the order parameters are examined to calculate the phase diagrams on the (D-z/J, T/J) and (D-x/J,T/J) planes for given values of the model parameters where D-x and D-z are respectively the transverse and longitudinal crystal-field components. It is found that the phase diagrams consist of second- and first-order phase transitions lines, in addition to the tricritical points and critical end-points that were observed. Negative values of D-z change fundamentally the topology of the system phase diagrams.