Growth, Band Structure and Optical Properties of LiSrBO3 Crystal

The bulk crystal of LiSrBO3 (8.39 g) with a size of 21mm×20mm×15mm was grown by high temperature solution growth method. The relationship between growth habit and crystal structure was discussed. The transmission spectrum shows an UV absorption edge at about 300 nm. The melting temperature of this crystal was determined to be 942 ℃ by DTA-TG measurement. The band structure of the LiSrBO3 crystal was studied by means of the first principle method. An indirect band gap was found to be about 4.0 eV,and a low dielectric constant was estimated to be about 1.9 in terms of theoretical results.     

Researches on the Growth Habit and Optical Properties of Fe^3＋ Ion Doped KDP Crystal

During the process of KDP crystal growth,metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper,KDP crystals were grown from an aqueous solution doped with different concentration of Fe3+ dopant by traditional temperature-reduction method and "point-seed" rapid growth method. Furthermore,we examined the light scatter and measured the transmission of these KDP crystals. It is found that the dopant of Fe3+ ion can improve the stability of the KDP growth solution when its concentration is less than 30 ppm. The effects of Fe3+ ion on the growth habit and optical properties of KDP crystal are also obvious.     

Bi_2O_3掺杂对Ag(Nb_(0.8)Ta_(0.2))O_3陶瓷结构和介电性能的影响(英文)

本文研究了Bi2O3掺杂对Ag(Nb0.8Ta0.2)O3陶瓷的结构和介电性能的影响。X射线衍射(XRD)结果表明,Bi2O3的掺杂可以使陶瓷中Ag+被还原并析出,且银析出的量随Bi2O3掺杂量的增加而不断增加,这可能源自于Bi3+对Ag+的取代。在一定范围内增大Bi2O3掺杂量可提高Ag(Nb0.8Ta0.2)O3陶瓷的室温介电常数,降低介电损耗,并使温度系数向负值方向移动。当Bi2O3的掺杂量约为3.5wt%时,样品具有较大的介电常数(ε=672)和较小的介电损耗(tanδ=7.3×10-4)。     

Bi2O3掺杂对Ag(Nb0.8Ta0.2)O3陶瓷结构和介电性能的影响

本文研究了Bi₂O₃掺杂对Ag(Nb_0.8Ta_0.2)O₃陶瓷的结构和介电性能的影响。X射线衍射(XRD)结果表明,Bi₂O₃的掺杂可以使陶瓷中Ag⁺被还原并析出,且银析出的量随Bi₂O₃掺杂量的增加而不断增加,这可能源自于Bi³⁺对Ag⁺的取代。在一定范围内增大Bi₂O₃掺杂量可提高Ag(Nb_0.8Ta_0.2)O₃陶瓷的室温介电常数,降低介电损耗,并使温度系数向负值方向移动。当Bi₂O₃的掺杂量约为3.5wt%时,样品具有较大的介电常数(ε=672)和较小的介电损耗(tanδ=7.3×10^-4)。     

Study on the Growth and Photorefractive Properties of In：Fe：Cu：LiNbO3 Crystals

Fe(0.2 mol%):Cu(0.04 mol%):LiNbO3 crystals with different doping concentration of In3+ (0, 1.0, 2.0, 3.0mol%) were grown by Czochralski method, and then oxidized and reduced. The infrared transmittance spectra of crystals were measured to investigate the location of doping ion and its threshold concentration. The photorefractive properties of the crystals were tested by two beam coupling experiment. The results showed that the threshold concentration of In ions is 2.0～ 3.0 mol% and In ions take the place of NbL 4i+ to form ( In L2i+) before reaching its threshold concentration, and then the location of normal Nb ions. In the (2.0 mol%):Fe:Cu:LiNbO3 crystal with the oxidation treatment having the highest diffraction efficiency (η = 45.8%), the photo-damage resistance threshold value R of In(3.0 mol%):Fe:Cu:LiNbO3 was 3.67×104 W/cm2 which was two orders of magnitude higher than that of Fe:Cu:LiNbO3 crystal (4.30×102 W/cm2). And the photo-damage resistance ability was enhanced by oxidized treatment. The In(2.0～3.0 mol%):Fe:Cu:LiNbO3 crystals with oxidized treatment have the best photorefractive properties.