Critical behavior and phase diagram of layered ferromagnetic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>FeTa</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">S</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math> single crystals
Azizur Rahman, Majeed Ur Rehman, Maryam Kiani, Hongze Zhao, Jianlin Wang, Yalin Lu, Keqing Ruan, Rucheng Dai, Zhongping Wang, Lei Zhang, Jian Wang, Zengming Zhang
Abstract
The magnetization of the highly air-stable two-dimensional (2D) intrinsic ferromagnet ${\mathrm{FeTa}}_{3}{\mathrm{S}}_{6}$ single crystal has been systematically investigated. Magnetization measurement revealed paramagnetic to ferromagnetic (PM-FM) phase transition at around 35 K and a strong magnetic anisotropy along the crystallographic c axis ($H\ensuremath{\parallel}c$). The critical exponents $\ensuremath{\beta}$ = 0.189(2), $\ensuremath{\gamma}$ = 1.423(1), and $\ensuremath{\delta}=8.531(7)$ with ${T}_{c}$ = 35 K suggest that the spin interaction of a two-dimensional (2D) Ising type in ${\mathrm{FeTa}}_{3}{\mathrm{S}}_{6}$ coupled with long-range ($\ensuremath{\sigma}=1.581$) interaction. A comprehensive magnetic phase diagram based on detailed magnetization measurements and universality scaling of ${\mathrm{FeTa}}_{3}{\mathrm{S}}_{6}$ is constructed over three magnetic field regions. The magnetic phase diagram of ${\mathrm{FeTa}}_{3}{\mathrm{S}}_{6}$ is analogous to that of ${\mathrm{CrNb}}_{3}{\mathrm{S}}_{6}$, which exhibits a chiral magnetic soliton lattice. DFT simulation reveals that the large magnetic anisotropy energy in ${\mathrm{FeTa}}_{3}{\mathrm{S}}_{6}$ originates from the combined effects such as considerable orbital magnetic moment, host lattice spin-orbit coupling, and hybridization between host lattice $2\mathrm{H}\ensuremath{-}{\mathrm{TaS}}_{2}$ and the intercalated Fe component. Furthermore, the magnetic anisotropy ($\ensuremath{\parallel}$ c) in ${\mathrm{FeTa}}_{3}{\mathrm{S}}_{6}$ is due to the dominant contribution of the spin conserving process $\mathrm{\ensuremath{\Delta}}{S}_{z}$ = 0 in magnetic anisotropy energy, which differs from that of ${\mathrm{CrNb}}_{3}{\mathrm{S}}_{6}$, or ${\mathrm{MnNb}}_{3}{\mathrm{S}}_{6}$, where the spin flipping process $\mathrm{\ensuremath{\Delta}}{S}_{z}$ = 1 dominates, causing in-plane ($\ensuremath{\perp}$ c) magnetic anisotropy.