Hydrothermal ion exchange on submillimeter-size single crystals of a new iron(III) phosphate

A direct ion exchange on single crystals of a new iron(III) phosphate Cs 4.65(3)K 4.35(1)Fe 7-(PO 4) 10 followed by single-crystal X-ray diffraction (SXRD) methods, employing mild hydrothermal conditions, is discussed. Single crystal of this iron(III) phosphate were immersed in 10 mL. of 1 M ANO 3 solution, where A=Li, Na, K, Rb, Cs), and heated in a Teflon-lined hydrothermal bomb at 200 °C. This new iron(III) phosphate reveals an almost perfectly ordered channel structure, which ensures low free energy for ion transport. The three-dimensional structure of this newly synthesized material contains interesting Fe 2O 10 dimers and Fe 3O 14 trimers interconnected by PO 4 tetrahedral units. These fused FeO n polyhedra have warranted the initial magnetic studies.