Critical behavior and magnetocaloric effect of the quasi-two-dimensional room-temperature ferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Cr</mml:mi><mml:msub><mml:mrow/><mml:mn>4</mml:mn></mml:msub><mml:mi>Te</mml:mi><mml:msub><mml:mrow/><mml:mn>5</mml:mn></mml:msub></mml:math>
Luo-Zhao Zhang, An-Lei Zhang, Xiu-De He, Xin-Wei Ben, Qi-Ling Xiao, Wenlai Lu, Fei Chen, Zhenjie Feng, Shixun Cao, Jincang Zhang, Jun‐Yi Ge
Abstract
A high-quality ${\mathrm{Cr}}_{4}{\mathrm{Te}}_{5}$ single crystal was prepared by the chemical vapor transport method. The crystal structure, magnetic properties, and magnetocaloric effect have been investigated in detail. Its critical behavior was methodically studied by measuring isothermal magnetization curves around the ferromagnetic to paramagnetic phase transition temperature. The critical exponents $\ensuremath{\beta}$ = 0.388, $\ensuremath{\gamma}$ = 1.29, $\ensuremath{\delta}$ = 3.93, and Curie temperature $T{}_{C}$ = 318.7 K were determined with modified Arrott plots, the Kouvel-Fisher method, critical isotherm analysis, and wisdom scaling law, respectively. The obtained critical exponents were self-consistent and follow the scaling equation around $T{}_{C}$, indicating the reliability of these values. Further analysis revealed that the spin coupling inside ${\mathrm{Cr}}_{4}{\mathrm{Te}}_{5}$ exhibits three-dimensional Heisenberg-like behavior with long-range magnetic interaction and that the exchange interaction decays as $J(r)\phantom{\rule{4pt}{0ex}}\ensuremath{\approx}\phantom{\rule{4pt}{0ex}}{r}^{\ensuremath{-}4.85}$.