Critical behavior and magnetocaloric effect in Mn$_3$Si$_2$Te$_6$

TL;DR

This study investigates the critical magnetic properties and magnetocaloric effect of Mn$_3$Si$_2$Te$_6$, revealing critical exponents, magnetic exchange behavior, and significant entropy change useful for magnetic cooling applications.

Contribution

The paper provides detailed critical exponents, analyzes magnetic exchange decay, and characterizes the magnetocaloric effect in Mn$_3$Si$_2$Te$_6$, a semiconducting ferrimagnet, which advances understanding of its magnetic phase transition and cooling potential.

Findings

Critical exponents $eta$, $ ext{and}$ $ ext{gamma}$ determined.

Magnetic exchange decay as $r^{-4.79}$ between models.

Large magnetic entropy change indicating strong magnetocaloric effect.

Abstract

The critical properties and magnetocaloric effect of semiconducting ferrimagnet Mn$_3$Si$_2$Te$_6$ single crystals have been investigated by bulk magnetization and heat capacity around $T_c$. Critical exponents $\beta = 0.41\pm0.01$ with a critical temperature $T_c = 74.18\pm0.08$ K and $\gamma = 1.21\pm0.02$ with $T_c = 74.35\pm0.05$ K are deduced by the Kouvel-Fisher plot, whereas $\delta = 4.29\pm0.05(3.40\pm0.02)$ is obtained by a critical isotherm analysis at $T = 74(75)$ K. The magnetic exchange distance is found to decay as $J(r)\approx r^{-4.79}$, which lies between the mean-field and 3D Heisenberg models. Moreover, the magnetic entropy change $-\Delta S_M$ features a maximum at $T_c$, i.e., $-\Delta S_M^{max} \sim$ 2.53(1.67) J kg$^{-1}$ K$^{-1}$ with in-plane(out-of-plane) field change of 5 T, confirming large magnetic anisotropy. The heat capacity measurement further gives $-\Delta S_M^{max}$ $\sim$ 2.94 J kg$^{-1}$ K$^{-1}$ and the corresponding adiabatic temperature change $\Delta T_{ad}$ $\sim$ 1.14 K with out-of-plane field change of 9 T.