Cr^(3+)∶LiNbO_3单晶的坩埚下降法生长及其特征研究  

Growth and characteristics of Cr^(3+)∶LiNbO_3 single crystal by Bridgman method

作　　者：夏海平[1] 王金浩[1] 曾宪林[1] 章践立[1] 张约品[1] 徐键[1] 聂秋华[1] 

机构地区：[1]宁波大学光电子功能材料重点实验室,浙江宁波315211

出　　处：《功能材料》2005年第2期238-240,共3页Journal of Functional Materials

基　　金：浙江省科技厅资助项目(011066);宁波市博士基金资助项目(02J20101 12)

摘　　要：用坩埚下降法技术,选用同成分化学计量的铌酸锂为初始原料,在合适的生长速度(1~4mm/h)与温度梯度(20~30℃/cm)下成功地生长出了无宏观缺陷、掺杂不同Cr3+离子浓度的铌酸锂单晶。测定了晶体的吸收光谱。Cr3+ 离子在晶体中以三价态存在,沿着生长方向晶体中 Cr3+ 离子的含量逐步减少。用顺磁共振谱(EPR)研究了晶体中 Cr3+离子的格位情况,结果表明Cr3+离子取代 Li 与 Nb 两种格位。测定了晶体的发射光谱并研究了发射强度随吸收强度的变化关系。The LiNbO3 crystals doped with Cr3+ ion (Cr:LN) in various concentration without macro-defects were grown by Bridgman method under proper conditions in congruent composition (Li/Nb = 48.6/51.4 in molar ratio), growth rate of l-3 mm/h, and a temperature gradient around 20-30°C/cm for solid-liquid interface. The absorption spectra of the obtained crystals were measured. The Cr ions exist in state of +3. The concentration of Cr3+ ion in crystal increased from lower to upper portion. Electron paramagnetic resonance had been used to investigate the sites occupied by the Cr3+ ions. Two Cr3+ ion centers located at Li+ and Nb5+ sites were observed. The fluorescence spectra were recorded and the relation between intensity of fluorescence and their absorption coefficient was investigated.

关 键 词：掺铬铌酸锂晶体 熔体晶体生长 坩埚下降法 格位 光谱 

分 类 号：TB381[一般工业技术—材料科学与工程]