Mossbauer and Magnetic Property Study on Cyano-bridged Compounds A3[Fe(CN)6]2•xH2O(A=Mn, Ni)

The cyano-bridged complexes A(3)[Fe(CN)(6)](2)center dot xH(2)O (A=Mn, Ni) have been synthesized. In the sample Mn-3[Fe(CN)(6)](2)center dot xH(2)O, XRD indicates that it has a face-centered cubic crystal structure with lattice constant of around 10 angstrom, SQUID tests here show that the samples which dry at 80 degrees C, 100 degrees C and 130 degrees C in vacuum have ferrimagnetic interactions, and their Curie temperature are about 9K, 8.8K and 7K respectively. The decreasing of their Curie temperature show that the charge transfer took place during the annealing. The free-dried Ni-Fe cyanide has the major structure of Fe-III-CN-Mn-II and a small number of Fe-II-CN-Mn-III. As the cyanide was annealed at higher temperature, Fe-III-CN-Mn-II gradually transformed into the structure of Fe-II-CN-Mn-III. In the sample Ni-3[Fe(CN)(6)](2)center dot 16.5H(2)O, The Fe-III-CN-Ni-II structure is the major structure in the freeze-dried Ni-Fe cyanide. And it has a small number of Fe-II-CN-Ni-III structure. As the cyanide was annealed at higher temperature, Fe-III-CN-Ni-II gradually transformed into the structure of Fe-II-CN-Ni-III, they are aslo show that the charge transfer took place during the annealing.