Inverse magnetocaloric effect in the spin-1/2 Fisher's super-exchange antiferromagnet

TL;DR

This paper rigorously analyzes the inverse magnetocaloric effect in an exactly solved spin-1/2 Fisher's super-exchange antiferromagnet, revealing significant effects near phase transitions and critical fields.

Contribution

It provides the first exact calculation of magnetocaloric properties in this model, highlighting the inverse effect around phase transitions and at critical magnetic fields.

Findings

Large inverse magnetocaloric effect near phase transition temperatures.

Maximum effect at the critical magnetic field of zero-temperature transition.

Exact analytical results for entropy and temperature changes in the model.

Abstract

The isothermal entropy change and the adiabatic temperature change for the exactly solved spin-1/2 Fisher's super-exchange antiferromagnet are rigorously calculated in order to examine magnetocaloric properties of the model in a vicinity of the second-order phase transition. It is shown that the large inverse magnetocaloric effect occurs around the temperature interval $T_c(h\neq0) < T < T_c(h=0)$ for any magnetic-field change $\Delta h: 0 \to h$. The most pronounced inverse magnetocaloric effect can be found for the magnetic-field change, which coincides with the critical field of a zero-temperature phase transition from the antiferromagnetically ordered ground state to the paramagnetic one.