Crystal structure reinvestigation and spectroscopic analysis of tricadmium orthophosphate

Single crystals of tricadmium orthophosphate, Cd₃(PO₄)₂, have been synthesized successfully by the hydro-thermal route, while its powder form was obtained by a solid-solid process. The corresponding crystal structure was determined using X-ray diffraction data in the monoclinic space group P2₁/n. The crystal structure consists of Cd₂O₈ or Cd₂O₁₀ dimers linked together by PO₄ tetra-hedra through sharing vertices or edges. Scanning electron microscopy (SEM) was used to investigate the morphology and to confirm the chemical composition of the synthesized powder. Infrared analysis corroborates the presence of isolated phosphate tetra-hedrons in the structure. UV-Visible studies showed an absorbance peak at 289 nm and a band gap energy of 3.85 eV, as determined by the Kubelka-Munk model.