Structural and Magnetic Investigations of the Novel Pyrophosphate Na7Ni3Fe(P2O7)4

A novel pyrophosphate Na7Ni3Fe(P2O7)4 was synthesized in two distinct forms, single-crystal and powder. Single-crystal X-ray diffraction used to determine the crystal structure, powder scanning electron microscopy were examine purity morphology of elaborated This phosphate crystallizes P1¯ space group triclinic system with a = 6.3677 (2) Å, b 9.3316 (4) c 10.8478 α 65.191 (1)°, β 80.533 (1)° γ 73.042 (1)°. The framework is assembled from linkage centro-symmetrical clusters Ni2(Ni/Fe)2P4O28. Each cluster consists (Fe1/Ni1)O6 octahedra, Ni2O6 octahedra P2O7 units. these provided by other units generate three-dimensional structure tunnels [100], [010] [001] directions, housing Na+ cations. infrared Raman analyses show characteristic bands anion P2O74−. Remarkably, magnetic investigations revealed coexistence transitions at ~29 K ~4.5 dominating antiferromagnetic interactions.