Modification of Calcium Orthovanadate Single Crystal Due to Cobalt Doping

Activation of calcium orthovanadate crystals by cobalt ions was carried out by introducing cobalt oxide into the melt during Czochralski growth process or during high-temperature annealing of nominally pure Ca3(VO4)2 single-crystal using Co3O4 powder as a solid-phase diffusant. The maximum concentration of the Co ions in the matrix is achieved in the case of the diffusion doping process. For the concentration series of Ca3(VO4)2:nCo crystals, the local structure was investigated and the crystal chemical composition was determined. Polarized absorption spectra of doped crystals are obtained. The influence of the atmosphere and the annealing temper-ature on the redistribution of the intensities of the characteristic absorption bands in the visible and near-IR spectral regions is shown. Luminescence parameters of the doped crystals were studied.