Critical behavior and magnetocaloric effect in quasi-two-dimensional Mn3Si2Se6

Abstract

The ferrimagnetic nodal-line semiconductor Mn3Si2Te6, featuring a quasi-two-dimensional crystal structure, has attracted significant attention owing to its rich physical properties. Here, we systematically investigate the magnetic properties of its isostructural compound, Mn3Si2Se6. The magnetism of this material is attributed to the Mn atoms, which exhibit antiferromagnetic interactions among the Mn atoms. The competition between antiferromagnetic exchange interactions results in an overall ferrimagnetic state, with a second-order transition from paramagnetic to ferrimagnetic occurring at 68 K. Critical exponents are derived using various common experimental techniques, including the modified Arrott plot, Kouvel-Fisher method, and critical isotherm analysis. The results indicate that the magnetism of Mn3Si2Se6 closely aligns with the mean-field model, with critical exponents β, γ, and δ determined as 0.475(3), 1.059(3), and 3.20(1), respectively, at the critical temperature of 68.3(2) K. Moreover, the curves of the magnetic entropy change − ΔSM(T, H) exhibit a peak around Tc, with −ΔSMmax amounts to 4.61 (3.63) J kg−1 K−1 for H∕∕ab (∕∕c) with a field change of 7 T. The estimated magnetic entropy value near Tc through specific heat is remarkably saller than the expected spin entropy of Mn2+ ions, indicating the presence of short-range interactions in the paramagnetic region.