Reserch Of Growth And Structure Characteristic Of Double Doped Lead Tungstate Single Crystals

The influence of dopants on the structure of PWO crystals was systematically studied, and main attention was focused on the relationship between the crystal components and structure, along with crystals grown technology, and equipment's mend.Experimentation mended grown equipment througth adding assistant heat source. This way reduces melting solid's temperature grids from the top down in the crucible, and resolve crystals protruding in the bottom. Perserving temperature's board which was designed with utilizing pulley resolved vision. Scientific research's men aren't harmed by vaporing lead with designing exhaust system. The crystals was grown by the Czochralski, due to the easier vaporization characteristics of PbO at the higher temperature and unsealed conditions, we found Pb deficient trend and W superabundance of melting solid.All kinds of PWO crystals showed the body-centered tetragonal structure in the Raman spectra. The peak related to Pb vibration was broadened due to Yb and Tb occupying the Pb or V_Pb position in the Raman patterns of doped PWO crystals. For Mo doping, the peak related to the W vibration in the outer model of WO42- groups was broadened. The broadened effect was enhanced with the increasing of dopants concentration. The peaks were shifted to the higher frequencies when the dopants were lighter than the occupied ions; otherwise the peaks were shifted to the lower frequencies. Compared with undoped PWO crystals, there were no new peaks in the X ray diffraction patterns of doped ones, merely the lattice constants are changed, namely the lattice constants became larger. VPb position was occupied at the higher dopants concentration, resulting in the decreasing of their concentration, the dopants was mainly substituted in the Pb²⁺ site. So, the lattice constants became smaller for those smaller doping ions; the constants became bigger for those larger ones. The effect of doping on the c constants was more obvious. And founding that dopants were substituted for VPb was superior to Pb²⁺.Doped ions affect the absorption edge and 420nm absorption. The absorption edge was shifted to the longer wavelength band when the polarization...