Critical phenomenon and phase diagram of Mn-intercalated layered MnNb3S6.

The magnetization of Mn-intercalated layered MnNb3S6 single crystal has been systematically investigated. The angle-dependent magnetization ([Formula: see text], [Formula: see text], and [Formula: see text]) displays that the magnetization of MnNb3S6 with [Formula: see text] is much stronger than that with H//c, but no magnetic anisotropy within the ab-plane. In addition, a field-induced magnetic phase transition is found when [Formula: see text]. The investigation of the critical behavior gives the critical exponents [Formula: see text], [Formula: see text], and [Formula: see text] with [Formula: see text] K, which belong to the universality class of three-dimensional Heisenberg model. The critical behavior and exponents indicate that the magnetic coupling in MnNb3S6 is of an isotropic short-range type. Based on universality scaling, the H  -  T phase diagram with [Formula: see text] is constructed. The magnetic behaviors and phase diagram of MnNb3S6 are analogous to those of CrNb3S6 which exhibits a chiral magnetic soliton lattice.