稀土硼酸盐的结构及其真空紫外(VUV)荧光性质

The Crystal Structure and VUV Luminescent Property of the Rare Earth Borates

稀土硼酸盐在真空紫外 (VUV)波段的吸收与化合物中硼酸根离子的结构有关 ,扩展 Hückel计算表明 ,硼酸根离子中的 B— O成键轨道与 B— O反键轨道能量差按 BO5- 4>B2 O4 - 5>BO3- 3 >B3O9- 9顺序减小 ,这与 VUV激发光谱的实验结果一致 ,表明 VUV激发过程对应于电子从 B— O成键轨道向反键轨道的跃迁 .

The VUV absorption of rare earth borates depends strongly on the structure of the borate ions. It is proposed from the simple extended Hückel calculation that the excitation transition in the VUV range is mainly from the B—O bonding orbital(HOMO) to the antibonding orbital(LUMO). The energy difference between the HOMO and LUMO decreases in the sequence of BO 5-_4>B_2O 4-_5>BO 3-_3>B_3O 9-_9, which accords with the VUV experimental results.