Co^(2+):BeAl_2O_4晶体的提拉法生长及光谱特性  

Growth of Co^(2+):BeAl_2O_4 Crystal by Czochralski Method and Their Spectroscopy

作　　者：夏海平[1] 张新民[1] 张约品[1] 章践立[1] 王金浩[1] 

机构地区：[1]宁波大学光电子功能材料重点实验室,宁波315211

出　　处：《人工晶体学报》2006年第4期854-857,共4页Journal of Synthetic Crystals

基　　金：高功率激光物理国家重点实验室资助项目(No.2006076)

摘　　要：应用提拉法,采用合适的化学组分配比和化料过程、以及选用适宜的固液界面温度梯度与生长速度等优化工艺条件,成功地生长出了初始Co2+离子掺杂浓度为0.15mol%、尺寸48×85mm2的优质Co2+:BeA l2O4晶体。测定了晶体的吸收光谱,观测到496与640nm二个主要吸收带,它们分别归属于八面体配位中Co2+的T1(4F)→4T1(4P)跃迁与四面体配位中Co2+的A2(4F)→4T1(4P)跃迁。从晶体的吸收光谱与呈现的粉红色颜色特征可推断大多数的Co2+离子取代BeA l2O4晶体中的A l3+,形成Co2+离子的八面体格位。研究了不同光波长激发下,晶体在可见光波段的荧光特征,观测到678nm波段的荧光发射,这归属于四面体格位中Co2+的电子从4T1(4P)到4A2(4F)能级的跃迁。The Co^2＋ ：BeAl2O4 crystal, initial doped Co^2＋ ion of 0.15 mol%, in the size of Ф48 × 85mm^2 with high quality was grown by the Czochralski （CZ） technique under the optimized conditions of choosing proper raw chemical compositions, taking reasonable melting process of the raw materials, using favorable temperature gradient of solid-liquid interface and growth rate. The absorption spectrum of Co^2＋： BeAl2O4 crystal was measured, and two main peaks at 496 and 640nm were observed. The peaks at 496 and 640 nm are assigned to the ^4T1 （^4F）→^4T1 （^4P） transition of Co^2＋ located in octahedral sites, and ^4A2 （^4F）→^4T1 （^4P）of Co^2＋ in tetrahedral sites, respectively. It could be deduced from the characteristics of absorption spectrum and their pink color of crystal that the majority of Co^2＋ ions substituted the Al^3＋ in BeAl2O4 crystal to form octahedral sites. The emission spectra of crystals in the visible region were investigated under excited with various lights, and the emission band 678nm was observed. The emission band at 678nm is assigned to the ^4T1 （^4P） - ^4A2（^4F） transition of Co^2＋ ions in tetrahedron.

关 键 词：铝酸铍晶体 提拉法 CO^2+离子 光谱 

分 类 号：TB381[一般工业技术—材料科学与工程]