Study Of The Thermodynamic Properties Of Random Transverse Field Mixed Ising Spin System With Crystal Field

This article mainly discusses the phase transition properties of random transverse field mixed spin ferromagnetic system with crystal field. The phase diagrams display the Curie temperature dependences of the crystal field, the transverse field and the trimodal random concentration for the honeycomb lattice and the square lattice. In the honeycomb lattice with random transverse field, a smaller crystal field cannot change the percolation threshold of critical transverse field. The reentrant phenomena shall appear at the range of certain random concentration when the transverse field takes a larger value, while the reentrant phenomena do not occur and when the transverse field take a smaller value. Due to the difference of coordination number, the honeycomb lattice and the square lattice display different transition properties. The existence a smaller crystal field can magnify magnetic ordering region at low temperatures and can depress one at high temperatures. The existence of a lager transverse field can also assist the occurrence of reentrant phenomena. Furthermore, when spin-1/2 and spin-1 sublattiees are of the different transverse fields and trimodal random distributions, they play a very different role. The study shows that the former is main reason of the reentrant phase transition of system, while the later is not contribute to reentrant phasetransition. On the other hand, when the crystal field is small, magnification of the range of magnetic ordering phase at low temperatures come from the contribution of spin-1 sublattice, while the result is not discovered in spin-1/2 sublattice. But influence of the crystal field on critical transverse fields of two different sublattices is very similar if the value of the crystal field increases to a certain degree.