Zinc-Diluted Magnetic Metal Formate Perovskites: Synthesis, Structures, and Magnetism of [CH3NH3][MnxZn1-x(HCOO)3] (x=0-1)

The preparation, structures, and magnetic properties of a series of metal formate perovskites [CH3NH3][MnxZn1-x(HCOO)3] were investigated. The isostructural solid solution can be prepared in the complete range of x=01. The metalorganic perovskite structures consist of an anionic NaCl type [MnxZn1-x(HCOO)3-] framework with CH3NH3+ templates located in the nearly cubic cavities and forming hydrogen bonds to the framework. When the proportion of Mn increased (i.e., x changed from 0 to 1), the lattice dimensions and metaloxygen and metalmetal distances show a slight, nonlinear increase because of the increased averaged metal ionic radius and the local structure distortion. Through the series, the magnetism changes from the long-range ordering of spin-canted antiferromagnetism for x=0.40 to paramagnetism when x=0.30, and the percolation limit was estimated to be xP=0.31(2) for this simple cubic lattice. In the low-temperature region, enhancement of magnetization and the gradual decrease and final disappearance of coercive field, remnant magnetization, and spin-flop field upon dilution were observed through this isotropic Heisenberg magnetic series. IR spectroscopic and thermal properties were also investigated.