河南产宝石级高温高压合成钻石的谱学特征及电磁性研究

为快速鉴定高温高压(HPHT)合成钻石,前人已开展了系统的发光特征和谱学特征研究,但对比性分析较少,且对电学性质和磁学性质关注不多.本文结合常规宝石学观察、高精度谱学测试以及导电性和磁性测试,对49粒无色、黄色样品进行了深入研究和对比分析.结果表明:①铁、钴、镍等金属元素的触媒残余是HPHT合成钻石的磁性来源,测试样品...

Spectral Characteristics and Electrical-Magnetic Properties of Gem-quality Synthetic Diamonds under High Temperature and Pressure

BACKGROUND:In order to quickly identify and screen high pressure and high temperature(HPHT)grown synthetic diamonds,a lot of research about their luminescent and spectral characteristics has been done.However,the comparative analysis is lacking,and less attention is paid to electrical and magnetic properties.OBJECTIVES:To summarize the spectral characteristics and investigate the electrical and magnetic properties of HPHT synthetic diamonds systematically.METHODS:Conventional gemological observation,high precision spectroscopy and electrical conductivity and magnetism testing were used for comparative analysis of 49 colorless and yellow samples.RESULTS:The residual metal catalysts,including iron,cobalt,and nickel,caused the ferromagnetism of diamonds.All of the HPHT synthetic diamond samples could be attracted by the magnetic bar with magnetic intensity up to 12000Gs.The colorless samples were typeⅡa+Ⅱb diamonds.The presence of boron led to its good conductivity,and the conductivity increased with increased boron content.The yellow samples were Ib+IaA type diamonds,and about one-third of the single nitrogen was converted into A aggregate.The synthetic diamond had undergone high temperature annealing treatment after growth.The ubiquitous presence of boron,and the presence of nitrogen mainly as single atoms and A aggregates led to the characteristic infrared spectra of HPHT synthetic diamonds.HPHT synthetic diamonds often contained crystal lattice defects caused by impurity elements such as nitrogen,nickel and silicon,which led to characteristic photoluminescence spectra.Colorless samples showed strong blue-green fluorescence and phosphorescence,whereas yellow samples had green fluorescence,with obvious cube-octahedron patterns.CONCLUSIONS:Spectral and luminescent characteristics are still an important basis for screening and identification of HPHT synthetic diamonds.HPHT synthetic diamonds under the current growth technology also have obvious differences from natural diamonds in both conductivity and magnetism,which can be used as an auxiliary basis for rapid identification.