Critical behavior of intercalated quasi-van der Waals ferromagnet Fe0.26TaS2

Abstract

In the present work, single-crystalline quasi-van der Waals ferromagnet $\mathrm{F}{\mathrm{e}}_{0.26}\mathrm{Ta}{\mathrm{S}}_{2}$ was successfully synthesized with Fe atoms intercalated at ordered positions between $\mathrm{Ta}{\mathrm{S}}_{2}$ layers. Its critical behavior was systematically studied by measuring the magnetization around ferromagnetic to paramagnetic phase transition temperature, ${T}_{C}\ensuremath{\sim}100.7\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, under different magnetic fields. The critical exponent \ensuremath{\beta} for the spontaneous magnetization below ${T}_{C}$, \ensuremath{\gamma} for the inverse initial susceptibility above ${T}_{C}$, and \ensuremath{\delta} for the magnetic isotherm at ${T}_{C}$ were determined with modified Arrott plots, the Kouvel-Fisher method, the Widom scaling law, and critical isotherm analysis, and found to be the following values: $\ensuremath{\beta}=0.459(6),\ensuremath{\gamma}=1.205(11)$, and $\ensuremath{\delta}=3.69(1)$. The obtained critical exponents are self-consistent and follow the scaling equation, indicating the reliability and intrinsicality of these parameters. A close analysis within the framework of renormalization group theory reveals that the spin coupling inside $\mathrm{F}{\mathrm{e}}_{0.26}\mathrm{Ta}{\mathrm{S}}_{2}$ crystal is of the three-dimensional Heisenberg $({d:n}={3:3})$ type with long-range magnetic interaction and that the exchange interaction decays with distance as $J(r)\ensuremath{\sim}{r}^{\ensuremath{-}4.71}$.