Growth, structural, IR and magnetic studies of a new gadolinium metaphosphate, Gd(PO3)3

The crystal structure of gadolinium metaphosphate Gd(PO3)3 has been established by X-ray diffraction. This compound crystallizes in the orthorhombic system (space group C2221, Z=4) with cell parameters: a=8.4530 (3), b=11.0576 (4) and c=7.1952 (2)A. The structure was refined to R1=0.0234 and wR2=0.0502 using 2180 independent reflections (I>2σ(I)). Phosphorus atoms are in slightly irregular tetrahedral oxygen coordination, gadolinium atoms are in considerably distorted dodecahedral oxygen coordination. Formally, the 3D framework in the structure can be described by the PO4 tetrahedra sharing corners to form helical chains and the GdO8 polyhedra sharing edges in a zigzag fashion. The shortest Gd-Gd distance is 4.174 (2)A. The infrared spectrum of the title compound recorded at room temperature in the frequency range of 400-4000cm-1, confirm the atomic arrangement within the structure. Below TC=25K, the magnetic susceptibility evolution is characteristic of a ferromagnetic order. In the high-temperature region above 100K, the susceptibility follows a Curie-Weiss law with C=7.91cm3Kmol-1 and θ=9.96K