蓝宝石的紫外-可见光谱及其致色机理分析

Analysis on UV-VIS Spectrumand Colouration Mechanism of Sapphire

蓝宝石的紫外-可见吸收光谱和能谱分析结果表明,蓝宝石从粉红色→紫色→蓝色→绿色→黄绿色→黄色,其Fe3+的浓度相对Fe2+-Ti4+离子对浓度由低至高变化;浅蓝色到深蓝色蓝宝石中的Fe和Ti均有所增加;褐色蓝宝石含有相对较多的Fe和Cr;Mn可能与蓝宝石的紫色有成因联系。热处理蓝色蓝宝石和辐照黄色蓝宝石在450,375,387nm处的吸收较未处理的弱,辐照黄色蓝宝石在405nm处有吸收带。

The XRF analyses and UV-VIS absorption spectra of sapphires with different colours indicate that the content of Fe^(3+) varies from the low to the high relative to the content of Fe^(2+)-Ti^(4+) with the colour shift from pink, purple, blue, green, yellowish green to yellow. The colour varies from light blue to dark blue with increasing of the contents of Fe and Ti. The brown sapphire is rich relatively in Fe and Cr. Irradiated yellow sapphire has absorption in 405 nm. Absorption in 450, 375, 387 nm of heat-treated blue sapphire and irradiated yellow sapphire is weaker than that of the untreated.