Study On The Defect Characteristics Of High Temperature And High Pressure Synthetic Diamond In A Chinese Company

Diamond is a precious material,whether in gemology,geology or materialogy.Many scientists devote themselves to study diamonds and their applications.Synthetic diamond perfectly solves the problem of the shortage of natural diamond as the substitute.Then we will research in synthetic diamonds of the better quality and applied to the specific field.In this paper,the study on the defect characteristics of large grain high-temperature and high-pressure synthetic diamond produced by a Chinese company is helpful to control the formation of defects during the growth process and extend the application range of synthetic diamond.According to the information,up to now,I have learned no one has conducted systematic research on the defect types,crystal lattice defect identification,defect characteristics and the distribution law of lattice defect of China's large grain synthetic diamond.This paper reviews the research on defects of diamonds by domestic and foreign scholars.The physical and chemical properties of diamond and the common impurities and defects are summarized.Common diamond synthesis methods include high-temperature and high-pressure?HPHT?and chemical vapor deposition?CVD?,different synthetic methods produce different defects in diamonds.Studied the gemological properties of the domestic large-gained HPHT synthesis diamond,and it can be found that the defects have effects on the surface characteristics,inclusion characteristics,fluorescence and phosphorescence,growth structure,abnormal birefringence and other aspects of the diamond.The sample contains many metal inclusion,abnormal birefringence often occurs around it,and its surface is mostly dendritic growth pattern.Application of Fourier Transform Infrared?FTIR?Spectrometer for sample testing and analysis.According to the FTIR spectrum can be found that there are three types of sample:yellow diamond have 1130 and 1344 cm^-1 infrared absorption peak,belong to?b type;blue diamond and part of colorless diamond contains 1290 and 2803 cm^-1 infrared absorption peak,and this is?b type diamond;the rest colorless diamond belong to?a type.Using the“mapping”function of the micro-infrared spectrometer to test the sample,it's shown that distribution of defects in the samples in uniform.The samples were tested with the ultra-sensitive photoluminescence?PL?instrument,some impurities such as Ni?N⁺can be detected.X-ray fluorescence spectrometer and UV-visible near-infrared spectrometer are used to test the sample,iron can be found in the sample.