明溪蓝宝石改色机理探讨

利用顺磁共振谱、红外光谱和热谱等方法，研究明溪蓝宝石的结构特性，分析结果表明，Fe主要以Fe^3 的形式存在，Fe^3 的d-d电子跃迁和Fe^2 -Ti^4 ，O-Fe间电荷转移是致色的主要因素。浓度差可以作为扩散动力，高温可以加速扩散的实现。OH^-位于晶格中，H的含量与蓝宝石蓝颜色有一定的正相关性，在改色工艺中，应注重控制Fe^2 的量和提高气氛中H的含量，以促进蓝色致色因子的进一步形成，去除杂色，改善蓝宝石的颜色。

An Inquiry into the Mechanism of the Colour Change of Sapphire Acquiring from Mingxi

By using the methods of nuclear magnetic resonance spectrometry and infrared spectrum and thermography, the authors conduct a study on the structural behaviour of sapphire acquiring from Mingxi. As indicated by the results, Fe exists mainly in the form of Fe 3+ , d d electron transistion of Fe 3+ and charge transfer between Fe 2+ Ti 4+ and O Fe are the main factors of colouration, concentration difference may serve as motive power of diffusion, and high temperature may accelerate the realization of diffusion. OH - is located between lattice, the content of H is positively correlated with the blue colour of sapphire to a certain degree. In technology of colour change, attention should be paid to the control of Fe 2+ amount and the enhancement of H content in the air, so as to promote further formation of blue coloration factor and to remove parti colour and to improve the colour of sapphire.