Critical behavior in the ferromagnet MgMn6Sn6 single crystal with HfFe6Ge6-type structure

A thorough investigation was carried out to analyze the magnetic critical properties of single crystals belonging to the HfFe6Ge6-type structure. MgMn6Sn6 exhibit a ferromagnetic transition below TC ≈ 300 K. The magnetization measurements were analyzed around the phase transition temperature of this ferromagnetic material for two different orientations: H//ab and H//c. Using Kouvel‐Fisher method, we can determine critical exponents β, γ, and δ in this study. To evaluate accuracy of these values, the scaling equation m=f±(h) and Widom scaling law δ=1+γ/β were applied. Critical exponents γ = 1.191 ± 0.007 at TC = 300.92 K, β = 0.326 ± 0.003 at TC = 300.96 K, and δ = 4.653 with TC ≈ 300 K indicate that the three-dimensional Ising model (β = 0.325, γ = 1.24, and δ = 4.82) is the better model for H//ab. The mean‐field and 3D‐Heisenberg models were the best models below TC and above TC for H//c, respectively. The MgMn6Sn6 single crystal exhibits a notable anisotropic transition in its magnetic phase according to all experimental findings. The presence of an anisotropic state with short-range order in the ferromagnetic system are revealed by analyzing electron spin resonance (ESR) spectroscopy. Our research provides experimental proof of a holistic comprehension regarding the magnetic phase-transition characteristics demonstrated by MgMn6Sn6.