High Resolution XRD Studies on Mg, Cr and Nd Doped LiNbO3 Crystals
Undoped and doped LiNbO3 single crystals were grown by Czochralski technique. Comparative studies on these undoped, Cr doped, Mg doped, Mg:Cr codoped and Mg:Nd codoped LiNbO3 single crystals were carried out. Phase identification was done using powder XRD technique. The effect of doping and co-doping on crystalline perfection of these crystals was monitored using high resolution x-ray diffraction (HRXRD) technique. The diffraction curves (DCs) were recorded in symmetrical Bragg geometry for (006) diffracting planes using MoK￻ 1 radiation. tant is co-doping with Mg or Zn at a level above 4.5 mol%, which inhibits photorefractive properties of the material. Another potential application of LiNbO3 is in Nd 3+ based compact diode-pumped self-frequency doubled lasers that emit green radiation, useful for applications in optical data storage, and excitation sources to replace ion gas lasers and pumping of parametric oscillators and amplifiers (10). The
Enhancement of structural perfection of alkali halide single crystals by doping with copper
Abstract The pure and copper (Cu + ) doped alkali halide single crystals have been grown from melt by using the Czochralski (Cz) method. The optical absorption studies confirm that the doped copper is incorporated with the grown crystals. The effect of doping on crystalline perfection of grown crystals was analyzed by high resolution X-ray diffraction (HRXRD) measurements. The HRXRD results clearly reveal that the Cu + doped crystals are having higher crystalline perfection than pure crystals. The mechanical behavior of the grown crystals was measured by the Vickers microhardness measurement. The hardness value of the crystals increases with an increase in load and thereafter it becomes independent of the applied load. The Meyer index number and hardness using Hays–Kendall approach of pure and doped crystals were calculated and tabulated.
Xα studies of laser crystals
This paper reports the spin-polarized self-consistent-charge discrete variational (SCC-DV-Xα) calculations for the garnets GGG(Ca, Mg, Zr), GGG, YGG and YAG. The calculated values of 10Dq for these garnets are reported for the first time, and are in good agreement with the experimental values. The relation between the calculated values and the distances of the central ion and the ligand ions is discussed. The energy values of the doublet state2Eg were also obtained, and the reason why YAG:Cr3+ only emits sharp fluorescence whereas GGG(Ca, Mg, Zr):Cr3+ can also emit strong broad fluorescence are explained.