Ⅰa型金刚石中水的显微红外光谱研究

Study on the Micro-infrared Spectra of Type Ⅰa Diamond

天然Ⅰa型金刚石在垂直于 ( 10 0 ) ,( 110 )和 ( 111)三个方向上定向显微红外光谱的定量比较分析表明 :水、片晶和C—C键在以上三个方向上所测得的浓度是不相同的。不同方向上水和片晶浓度的变化趋势基本相同 ,表明样品中水与片晶具有密切伴生的特征。

Because of the lattice restriction in diamond, impurities (e.g.H 2O) have different distributions in different directions and locations . This is different from liquid. With the help of micro IR we can gain different concentrations of impurities in different directions of the same sample, then the distribution rule of the impurity can be analyzed . On the basis of the orientated micro infrared spectrum data which are contrasted quantitatively , we find that there are different concentrations of H 2O, platelets and C-C bond in the direction vertical to (100) , (110) and (111) in type Ⅰa diamond. H 2O and platelets are accompanying because they have the same concentration tendency from the direction vertical to (100) to the direction vertical to (110) and (111) . This result is different from the distribution rule of H 2O in diamond suggested by other workers . At the same time,we think certain ratio of H 2O to nitrogen ( ε platelet / ε H 2O) is useful to the synthesis of type Ⅰa diamond.