Dynamic dipolar and quadrupolar susceptibilities for the spin-1 Blume-Emery-Griffiths model based on Onsager theory of irreversible thermodynamics

The expressions for dynamic (complex) dipolar and quadrupolar susceptibilities are obtained within the framework of the linear theory of irreversible thermodynamics in the Blume-Emery-Griffiths model. Frequency, temperature as well as crystal field dependences of the dispersion relations and absorption factors are investigated for two different phase diagram topologies which take place for K/J = 3 and K/J = 5.0. Their behaviors near the second- and first-order transition points as well as multi-critical points such as tricritical, triple and critical endpoint are presented.