Three-dimensional critical behavior and anisotropic magnetic entropy change in quasi-two-dimensional LaCrSb3

Abstract

The critical properties and magnetic entropy change of quasi-two-dimensional ${\mathrm{LaCrSb}}_{3}$ single crystals have been systematically investigated. The ferromagnetic transition is determined to be of a second order. Critical exponents $\ensuremath{\beta}=0.298(7)$ with a critical temperature ${T}_{c}=132.0(2)$ K and $\ensuremath{\gamma}=1.277(9)$ with ${T}_{c}=132.5(3)$ K are yielded by the modified Arrott plot, whereas $\ensuremath{\delta}=5.28(9)$ is deduced by a critical isotherm analysis at $T=132$ K. The critical exponents of quasi-two-dimensional ${\mathrm{LaCrSb}}_{3}$ exhibit a three-dimensional critical behavior. The magnetic interaction is found to be of a long range and the magnetic exchange distance decays as $J(r)\ensuremath{\approx}{r}^{\ensuremath{-}4.9}$, which lies between the mean-field model and 3D Heisenberg model. Furthermore, the magnetic entropy change $\ensuremath{-}\mathrm{\ensuremath{\Delta}}{S}_{M}$ features a maximum around ${T}_{c}$, i.e., $\ensuremath{-}\mathrm{\ensuremath{\Delta}}{S}_{M}^{\text{max}}\ensuremath{\sim}3.4$, 5.9, and $5.8 \mathrm{J} {\mathrm{kg}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ for a field change of 5 T applied the $H//a, b$, and $c$ axes, respectively. The rotating magnetic entropy change $\mathrm{\ensuremath{\Delta}}{S}_{M}^{R}(T,H)$ between the $a$ and $b$ axes (the $a$ and $c$ axes) reaches a maximum value of $2.55 (2.49) \mathrm{J} {\mathrm{kg}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ around ${T}_{c}$, exhibiting strong anisotropic features. However, $\mathrm{\ensuremath{\Delta}}{S}_{M}^{R}(T,H)$ between the $b$ and $c$ axes is $\ensuremath{\sim}0 \mathrm{J} {\mathrm{kg}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ at $T>{T}_{c}$ displaying a nearly isotropic behavior, and is less than $0.3 \mathrm{J} {\mathrm{kg}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ at $T<{T}_{c}$ showing weak anisotropy.