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VO 2+ ions-doped CaZn 2 (PO 4) 2 nanophosphor was prepared through solid-state reaction technique. The synthesized phosphor was subjected to various spectroscopic characterizations such as powder X-ray diffraction (P-XRD), Fouriertransform infrared spectroscopy (FT-IR), optical absorption and electron paramagnetic resonance (EPR). XRD pattern confirmed that the structure of the sample belongs to triclinic system. The average grain size was found to be 82.23 nm. FT-IR spectrum exhibited characteristic vibrational modes of phosphate (PO 4 3−) ion along with other bands. Optical absorption spectrum displayed three peaks at 436, 690 and 827 nm, suggesting C 4v symmetry with crystal field and tetragonal field parameters Dq = 1449, Ds = − 2990 and Dt = 624 cm −1. The g and A values from EPR spectrum are determined as g ║ = 1.9433, g ┴ = 1.9891, A ║ = 171.2 and A ┴ = 73.4 × 10 −4 cm −1. Correlation of optical and EPR data revealed that VO 2+ ions have tetragonally distorted octahedral symmetry and have covalent bonding nature with ligands.

Cu 2+ ions doped CaZn 2 (PO 4 ) 2 nanophosphor was prepared by solid-state reaction (SSR) method. The synthesized material was studied by different characterization techniques like X-ray diffraction, Fourier Transform Infra Red, optical absorption and Electron Paramagnetic Resonance (EPR) techniques. The diffraction pattern exhibited the prepared sample belongs to the triclinic crystal structure and average grain size of the crystalline sample was determined as 82 nm. From the EPR spectrum, the bonding parameter and the calculated values of spin-Hamiltonian parameters suggest that Cu 2+ ions have rhombically distorted octahedral site symmetry. Absorption spectrum contains four bands observed at 689, 830, 1050, and 1207 nm which are due to the transitions 2 A 1 (d x 2 -y 2 ) → 2 B 2 (d yz ), 2 B 1 (d xz ), 2 A 1 (d xy ) and 2 A 1 (d z 2 ) respectively. The Fourier transformed infra red spectrum exhibited fundamental vibration frequencies of Phosphate (PO 4 3-) ions along with other functional groups.