01-36U
01-36U
Investigation of magnetic field influence on thermodynamic characteristics of spin-1 Ising model of a magnet with bilinear and quadupolar interactions. Cluster approximation
Influence of external magnetic field on spin-1 Ising magnet with bilinear and quadupolar interactions is studied within the cluster approximation. Phase diagrams in the (magnetic field, temperature) plane are constructed at different values of quadrupolar interaction. Temperature dependences of magnetization, quadrupolar moment, and static suscepbtibility are obtained at different values of the model parameters. We show that at those values of the quadrupolar interaction when at zero magnetic field the system undergoes the temperature phase transition between quadrupolar and paramagnetic phases, the external magnetic field not only induces a non-zero magnetization in "paramagnetic" and "quadrupolar" phases, but also can split this transition into a cascade of phase transitions: "quadrupolar" $\rightarrow \mskip \thickmuskip $ferromagnetic $\rightarrow \mskip \thickmuskip $"paramagnetic" phase.