Investigation of magnetic phase transition on the layered inorganic-organic hybrid perovskites (C₆H₅CH₂CH₂NH₃)₂MnCl₄ by single-crystal neutron diffraction

In previous work, the inorganic-organic hybrid perovskite system (C₆H₅CH₂CH₂NH₃)₂MnCl₄ exhibit well-isolated 2D Heisenberg antiferromagnetc properties, including a canted antiferromagnet below T_N = 44.3 K. This study looked at the antiferromagnetic spin structure of the titled compound using single-crystal neutron diffraction. At 43 K, a new forbidden (−1 0 0) peak was observed and this peak showed a clear temperature dependence. Additionally, non-integer forbidden peaks were found. It was assumed that the magnetic cell was equal to the chemical cell for Mn-PEA system (k = 0). No magnetic peaks were observed along the c-axis. From this data it can be assumed that the spin is parallel to the c-axis. This result coincides with previous magnetic measurement studies. According to Turov, in the case of an antiferromagnetic structure with weak ferromagnetism, the magnetic cell should be equal to the chemical cell. Our neutron diffraction measurement and former study strongly support the hypothesis of Turov.