Canted antiferromagnetism and spin reorientation transition in layered inorganic-organic perovskite (C6H5CH2CH2NH3)2MnCl4.

This work presents the synthesis, structure determination and magnetic properties of a new complex, phenethylammonium tetrachloromanganate(II), (C(6)H(5)CH(2)CH(2)NH(3))(2)MnCl(4) (Mn-PEA). Single crystals of Mn-PEA were obtained from methanol solution using the solvent-evaporation method at room temperature. The crystal structure of Mn-PEA was determined by single-crystal X-ray diffraction (orthorhombic, space group Pbca, a = 7.2075(9), b = 7.3012(14), c = 39.413(6) Å and Z = 4). The structure consisted of an extended [MnCl(4)](2-) network and two phenethylammonium cations to form a two-dimensional halide perovskite structure. Temperature-dependent magnetization measurements indicated that Mn-PEA acted as a weak ferromagnet below T(C) = 44.3 K due to spin canting. Below T(C), the magnetic behavior differed significantly from the behavior commonly observed among weak ferromagnets. The susceptibility depended strongly on the crystal orientation, the external magnetic field strength, and the magnetic history. The isothermal magnetization for two orientations revealed a ferromagnetic moment with a spin-canting angle of 0.04° and a spin-flop transitions with H(sf) = 3.5 T. The weak ferromagnetism, which manifested as spontaneous magnetization and magnetic hysteresis near a field strength of zero, was driven by interplay between the easy axis and the antisymmetric Dzyaloshinsky-Moriya (DM) interaction, leading to directional dependent magnetic behavior.