Field-dependent anisotropic room-temperature ferromagnetism in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Cr</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>
Aina Wang, Azizur Rahman, Zan Du, Jun Zhao, Fanying Meng, Wei Liu, Jiyu Fan, Chunlan Ma, Min Ge, Li Pi, Lei Zhang, Yuheng Zhang
Abstract
Materials hosting intrinsic room-temperature ferromagnetism have significant application in spintronics. In this context, the transition metal sulfide chromium telluride (${\mathrm{Cr}}_{x}{\mathrm{Te}}_{y}$) has sparked significant attention due to its room-temperature ferromagnetism, as well as high magnetic anisotropy, easy tunability, and air stability. This study carefully examines the magnetic characteristics of an intrinsic room-temperature ferromagnetic ${\mathrm{Cr}}_{3}{\mathrm{Te}}_{4}$ single crystal. Magnetization measurements identify a paramagnetic-to-ferromagnetic (PM-FM) phase transition at ${T}_{C}\ensuremath{\sim}322$ K and high magnetic anisotropy. Meanwhile, a coexistence of ferromagnetism and antiferromagnetism is unveiled below ${T}_{N}\ensuremath{\sim}90$ K. A systematic investigation of magnetization isotherms collected near ${T}_{C}$ provides the asymptotic critical exponents $\ensuremath{\beta}=0.365(5), \ensuremath{\gamma}=1.212(9), \ensuremath{\delta}=4.580(4)$ for $H//ab$, and $\ensuremath{\beta}=0.370(3), \ensuremath{\gamma}=1.329(1), \ensuremath{\delta}=4.554(9)$ for $H//c$. The obtained critical exponents for $H//ab$ and $H//c$ suggest strong anisotropic and multiple magnetic interactions in ${\mathrm{Cr}}_{3}{\mathrm{Te}}_{4}$. The comprehensive $H\ensuremath{-}T$ phase diagrams for $H//ab$ and $H//c$ are constructed using universal scaling and detailed magnetization, revealing strong field-dependent anisotropic room-temperature ferromagnetism and coexistence of ferromagnetism, antiferromagnetism, and noncollinear ferromagnetism. The multiple phases demonstrate that the magnetic couplings in ${\mathrm{Cr}}_{3}{\mathrm{Te}}_{4}$ are mediated by intralayer super exchange, interlayer double exchange, and direct exchange.