PbWO_4的偏振吸收光谱及400nm吸收带的结构起因

Polarized light absorption spectra of PbWO_4 and the origin of 400nm absorption bands

用改进的Bridgeman方法生长了PbWO4晶体。分别测量了晶轴垂直和平行于表面的该PbWO4晶体样品的吸收谱,同时测量了晶轴平行于表面的偏振吸收谱。结果显示吸收谱在350nm处有一弱吸收带,在400nm处有一强吸收带,在500nm～700nm处有一宽带。400nm的强带在偏振光吸收谱中不显示出二向色性,从而归因于三价铅离子心(Pb3+)。

The PbWO_4 sample is produced by modified bridgeman method. Optical absorption spectra of the samples with the crystal axis C perpendicular and parallel to the surface and the spectra on polarized light of the sample with the C parallel to its surface are measured respectively. The spectra exhibit a 350nm weak band, a 400 nm strong band and a wide band at 500nm～700nm. The 400nm band occurs no dichroism under polarized light absorption and is ascribed to the Pb^(3+) center.