HTHP合成钻石在首饰中的鉴别特征（上）

采用宝石显微镜、红外光谱仪、X荧光光谱仪、紫外-可见光分光光谱仪、紫外荧光灯、Diamond View等对HPHT合成钻石做了较详细的测试与分析。结果表明：这些HTHP合成钻石具有较为一致的黄色,放大检查可见合成钻石内部含有大量棒状、柱状、细小微粒状的铁镍合金包裹体,这些合成钻石几乎都有磁性甚至有些磁性较强。HTHP合成钻石的红外反射光谱非常特征均具有明显的1131cm-1的吸收峰,为Ib型钻石（此类钻石在天然钻石中极少见到）。HTHP合成钻石在X荧光光谱仪下有强烈的铁峰和镍峰,并且在短波紫外线下多数具有绿黄色荧光。HTHP合成钻石在Diamond View下具有不同程度的黄绿色荧光,个别具有黑十字现象。     

高温高压法合成钻石的宝石学特征

采用宝石显微镜、红外光谱仪、X荧光光谱仪、紫外荧光灯、Diamond View~(TM)等对济南某公司生长的高温高压合成的黄色、无色、蓝色钻石样品进行详细地测试与分析。结果表明,高温高压合成钻石放大观察可见内部含有棒状、柱状、细小微粒状的金属包裹体,个别样品内部相对纯净,净度级别可达VS_1;红外吸收光谱测试显示,无色合成钻石为IIa型,黄色合成钻石为Ib型,蓝色合成钻石为IIb型。X荧光光谱测试显示所有钻石都具有强烈的铁峰,无色和蓝色合成钻石未检出镍,5号样品检测出铁和镍,6号样品检测除铁和镍外还有锰。无色和蓝色合成钻石在Diamond View~(TM)下具有蓝白色荧光,并具有磷光现象且发光时间可达60多秒;合成黄色钻石在Diamond View~(TM)下具有黄绿色荧光,无磷光现象。这些高温高压合成钻石都具有"黑十字"现象,并可见四边形生长环带。紫外-可见光分光光谱仪测试合成钻石,均未检测到415nm吸收线。     

一例充填海蓝宝石戒面的宝石学特征研究

采用宝石显微镜、折射仪、紫外灯等常规宝石学测试方法,结合红外吸收光谱仪、紫外可见光谱仪、Diamond ViewTM荧光观测仪、X荧光光谱仪等大型仪器对一粒经充填处理的海蓝宝石戒面进行系统分析研究,结果表明:该样品在宝石显微镜下采用透射光观察具有紫红色闪光现象.紫外灯下可见裂隙面具有蓝绿色荧光,在Diamond Vie...     

一粒经辐照处理的蓝色钻石的鉴定特征

曾在日常检测中遇到一粒蓝色钻石,经宝石显微镜、紫外荧光灯、红外光谱仪、紫外-可见光光谱仪测试,结果显示:样品在宝石显微镜下具有钻石特征,但缺陷处颜色深,并且样品具有暗红的荧光。红外光谱显示该钻石属于ⅠaAB型钻石,紫外-可见光光谱测试发现样品具有739.9nm吸收峰,揭示了样品经过了辐照处理。     

一粒具强磷光的天然Ⅱa型无色钻石的宝石学及光谱学特征

以1粒具强磷光的Ⅱa型无色钻石作为研究对象,对其宝石学特征和谱学特征进行测试分析。结果显示,该样品在正交偏光下出现条带状干涉色,红外光谱结合紫外可见光谱确定为Ⅱa型钻石,Diamond View TM钻石观察仪下观察具橙红色荧光和网状多边形结构,并伴有罕见的强蓝色磷光。光致发光光谱显示NV 0中心、NV-中心、B-interstitial中心和B-V中心。经上述综合分析,该样品为天然Ⅱa型钻石,未经高温高压改色处理,其橙红色荧光由NV 0中心和NV-中心共同贡献,蓝色磷光的产生可能与B-interstitial中心和B-V中心有关。在日常检测过程中,对于此类Ⅱa型钻石的鉴定应全面分析,避免误判。     

荧光氧化石墨烯的合成与发光性能

通过将氧化石墨烯进行胺化反应,在其表面修饰上甘氨酸,合成出了具有很强蓝色荧光的荧光氧化石墨烯。通过荧光仪、紫外可见分光光谱仪、傅氏转换红外线光谱分析仪等表征手段对甘氨酸修饰的氧化石墨烯进行表征,结果表明,甘氨酸是以共价键的形式修饰在氧化石墨烯上的,1.0mg/m L的甘氨酸修饰的氧化石墨烯在紫外灯下就能表现出很强的蓝色荧光,当用360nm紫外激光激发甘氨酸修饰的氧化石墨烯时,可以检测到在450nm处有一个很强的发射峰。     

基于百香果壳的荧光碳量子点的制备及对Fe3+的检测

以百香果壳为原材料,采用水热法合成荧光碳量子点(CQDs),考察了碳量子点(CQDs)对Fe³⁺的检测效果。利用透射电子显微镜(TEM)、X射线衍射(XRD)、红外光谱仪(FT-IR)、紫外-可见吸收光谱仪、荧光光谱仪等对碳量子点(CQDs)的形貌、结构、基团、光谱特性等进行了表征。结果显示,合成的碳量子点形貌和分散性良好,尺寸约为7 nm。在435 nm的激发波长下,其发射峰位于512 nm处。在反应温度为120℃,反应时间为12 h时,所得到的碳量子点的性能最好。Fe³⁺对CQDs荧光有明显的猝灭现象,而其他金属离子的加入不会改变CQDs的荧光强度及发射峰位置,说明合成的CQDs可以实现对Fe³⁺的特异性检测。     

X射线荧光光谱仪及其分析技术的发展

按照获得和分辨特征X射线荧光光谱的方式,X射线荧光光谱仪可以分为波长色散X射线荧光光谱仪（WDXRF）和能量色散X射线荧光光谱仪（EDXRF）两大类。依照这一分类,论述了X射线荧光光谱仪在设备装置和配套方法方面的新状况。X射线荧光光谱仪整机现在向着小型化、智能化、多功能方面发展,仪器各部件也随着研究的深入而得到了更进一步地改进,在这一基础上,仪器可分析元素的含量范围得到了拓展,方法也得到了丰富。目前,X荧光光谱仪开发了微区面分布的元素成像分析方法、高级次谱线分析方法、薄膜分析方法等新的方法,对这些新方法作以介绍,同时也对基本参数法（FP法）的新近发展作了说明。     

一例孔雀石仿制品的宝石学特征

对一件外观酷似孔雀石的样品进行常规宝石学特征测试,结合红外吸收光谱仪、紫外可见光谱仪、X荧光光谱仪分析,结果表明,样品折射率为1.576,长波紫外灯下具有黄绿色荧光,X荧光光谱分析主要含Ba和Sr元素,红外吸收光谱测试特征吸收峰为609cm~(-1)、636cm~(-1)、702cm~(-1)、748cm~(-1)、984cm~(-1)、1080cm~(-1)、1123cm~(-1)、1188cm~(-1)、1285cm~(-1)、1377cm~(-1)、1454cm~(-1)1493cm~(-1)、1601cm~(-1)、1639cm~(-1)、1732cm~(-1)、2858cm~(-1)、2936cm~(-1),紫外可见光谱分析与孔雀石谱图存在明显差别,经上述分析确定样品为醇酸树脂有机物和重晶石的混合物。     

HTHP处理钻石的结构缺陷与颜色转变机制

通常褐色钻石可能伴随着塑性变形,在滑移面附近可能有一个高浓度的断键。当这些钻石在合成钻石生长的温压条件下,滑移面的一些破裂处可能会开始愈合,并会导致一部分空穴和间隙被释放。被释放的空穴会发生移动,与不同形式的氮结合产生新的色心,将使得钻石经HTHP处理后呈现不同的颜色。研究表明,褐色钻石经HTHP处理后呈黄色,主要与H3心、H4心、N3心和孤氮有关;处理后呈绿色或黄绿色,主要与H2心、H3心有关;处理后呈红色,主要与较高浓度的(N-V)-心有关;IIa型钻石处理后呈白色,则主要由于空穴与间隙一起消失湮没,与不能产生新色心有关。     

Optically stimulated luminescence (OSL) and laser excited photo luminescence of electron beam treated (EBT) diamonds: Radiation sensitization and potential for tissue equivalent dosimetry

We report the first optically stimulated luminescence (OSL; blue light stimulated luminescence (BLSL) and infrared light stimulated luminescence (IRSL)) results on colored diamonds and present experimental evidence that electron beam treatment (EBT) increases the radiation sensitivity of diamonds to a level that makes them suitable for low level radiation dosimetry. A suite of seven samples was examined. These comprise a white, three brown and three yellow diamond pieces. The FT-IR spectra of these diamonds revealed the nature and concentration of nitrogen impurity. The white diamond was kept as a control. The brown and yellow (with varied saturation) diamonds were irradiated by a 1.7 MeV electron beam. These turned blue/dark green; three of them were then heated in vacuum in the temperature range of 850-900 °C for two hours. Heating turned the irradiated diamonds to lemon yellow, pink, and purple colors. The irradiated and unheated blue samples were designated as 2C and 2D.The control sample, an un-irradiated white type Ia diamond, did not yield any significant IRSL/BLSL with doses up to 100 Gy. The BLSL/IRSL sensitivity of irradiated and heat treated diamonds was very poor, and depended on the heat cycle and hence were not pursued. Sample 2C exhibited significant BLSL and negligible IRSL sensitivity. Sample 2D gave an intense orange red emission under IR excitation as also responded to BLSL. The dose response of the BLSL signal in 2C suggested a minimum detectable dose of ~ 0.1 Gy and its use as a tissue equivalent dosimeter.Based on supporting experiments such as laser excited photoluminescence, we suggest that the BLSL process in 2C is primarily driven by carbon vacancies, which release a mobile hole when excited by GR2 band in the blue region. BLSL intensity exhibited a maximum around 285 °C. Given that TL glow peak also occurs near this temperature and that the nitrogen-interstitial carbon (N-Ci) complex also forms at this temperature (as reported in the literature), and it appears that the e-h recombination at sites with N-Ci complex could be involved in BLSL production. Laser excited photoluminescence (PL) at wavelengths 325, 514 and 785 nm and absorption spectra in UV-Visible range gave insights into the contrasting BLSL/IRSL responses of 2C and 2D. These differences were due to differences in nitrogen impurity complexes and the concentration of carbon vacancies produced by EBT in 2C and 2D. In 2D, the presence of Ni as NE8 center (four nitrogens coordinated to Ni) giving 800 nm emission on 785 nm excitation, appeared to suppress BLSL and sensitize IRSL in the orange window.     

Synthesis of HPHT diamond containing high concentrations of nitrogen impurities using NaN3 as dopant in metal-carbon system

Diamond crystals have been synthesized from FeNi alloy — carbon system under high pressure and temperature of 5.0 to 5.8 GPa and 1500 to 1750 K. Concentrations of the nitrogen impurities of the crystals have been determined from FTIR spectra, and it is found that the concentrations of single substitutional nitrogen impurities exceeds 1000 ppm, when NaN₃ is added as dopant to the metal-carbon system. The crystals are 0.2–0.5 mm in diameter with cubo–octahedral morphology, although octahedron and cube were also found in the diamond products. They exhibit yellow green to deep green color.     

Effects of the additive NaN3 added in powder catalysts on the morphology and inclusions of diamonds synthesized under HPHT

In this paper, the effects of the additive NaN₃-added in powder catalysts to synthesize nitric diamond were studied in a cubic anvil high-pressure and high-temperature apparatus (SPD-6 × 1200). Diamond crystals with perfect shape were successfully synthesized using NaN₃-added Fe₉₀Ni₁₀ catalyst under pressure 5.4 GPa and temperature 1600 K for 15 min. The temperature and pressure of crystals growth were increased with an increase of the content of NaN₃. The V-shape section for the diamond's growth, which is the region between the solvent/carbon eutectic melting line and diamond/graphite equilibrium line under pressure and temperature, was moved upwards. The synthetic diamonds exhibited perfect cubo-octahedral shape or octahedral shape with green or densely green in color. However, some orderly accidented lines were observed on the surfaces of most of the diamond crystals synthesized with NaN₃-added in Fe₉₀Ni₁₀. These lines might be formed during the procedure of crystal growth according to the results of the scanning electron microscope images. Moreover, the Mössbauer spectrometry for these diamonds indicated that the concentrations of inclusions formed by iron in diamonds were changed and iron nitride was detected.     

Synthesis of diamond with high nitrogen concentration from powder catalyst-C-additive NaN3 by HPHT

Diamond crystals with high nitrogen concentration, 1000-2000 ppm, have been successfully synthesized from the system of powder catalyst (Fe-Ni)-C-additive NaN₃ in a cubic anvil high-pressure and high-temperature apparatus. The synthetic diamond crystals are cubo-octahedral or octahedral shape with a green or dark green color. The FTIR spectra of the diamond synthesized indicate that its nitrogen concentration increases with an increase of the NaN₃ additive. Furthermore, such additive increase also leads to an increase in the minimum temperature and pressure for graphite/diamond conversion. We found iron nitride in the sample synthesized with high content of NaN₃. We believe its presence is an indication that Fe content in the Fe-Ni alloy is reduced and the characteristics of catalyst are changed, leading to the increase of the minimum temperature and pressure for graphite/diamond conversion.     

褐黄色IaA＋Ib型合成金刚石的光谱测试分析（下）

通过对褐黄色合成金刚石样品进行常规宝石学、红外光谱、紫外—可见光分光光度计,拉曼光谱等测试,结果表明：金刚石结构中的氮作为金刚石中的一种主要杂质,是金刚石呈现颜色的重要原因,并可用能带理论来解释,结构中的氮在金刚石呈色机制研究上有重要的意义。文章重点研究褐黄色合成金刚石的颜色成因,指出金刚石的呈色机制是一个很复杂的问题,它与金刚石中的杂质成分、色心、缺陷均有关系。     

Mechanical properties of synthetic type IIa diamond crystal

The mechanical behavior of synthetic type IIa diamond has been investigated by the Knoop hardness measurement and observation of the cleavage surfaces. It was clarified that the Knoop hardness in (100)100 of synthetic diamonds increases with decreasing of the nitrogen impurities concentration, and that the synthetic type IIa diamond, having few nitrogen impurities, has the highest hardness of synthetic diamonds. In addition, it was found that the Knoop hardness in (100)110 of synthetic type IIa diamond is extremely high, and the anisotropy in the hardness of the diamond is different from those of natural diamond and synthetic type Ib diamond. The cleavage surfaces of the synthetic type IIa diamonds were very smooth and showed remarkably regular cleavage patterns. These results indicate that there are very few impurities and crystal defects in the synthetic type IIa diamond, and also suggest that the diamond has high resistance to plastic flow.     

褐黄色IaA＋Ib型合成金刚石的光谱测试分析（上）

通过对褐黄色合成金刚石样品进行常规宝石学、红外光谱、紫外一可见光分光光度计,拉曼光谱等测试,结果表明：金刚石结构中的氮作为金刚石中的一种主要杂质,是金刚石呈现颜色的重要原因,并可用能带理论来解释,结构中的氮在金刚石呈色机制研究上有重要的意义。文章重点研究褐黄色合成金刚石的颜色成因,指出金刚石的呈色机制是一个很复杂的问题,它与金刚石中的杂质成分、色心、缺陷均有关系。     

Growth of high purity large synthetic diamond crystals

This paper reviews achievements at the Diamond Research Laboratory where, in the past, large, nitrogen-containing type Ib crystals of up to 25 ct in weight have been synthesised by the temperature gradient method. Further work has focused on reducing the nitrogen point defect incorporation in synthetic diamond by introducing nitrogen getters into the synthesis cell used for this growth process. This has enabled the synthesis of large type Ia diamonds up to 4.6 ct in weight, containing nitrogen from 0.01 to 0.4 ppm. Large type IIb diamonds, up to 5.1 ct in weight, have also been synthesised by adding boron to the synthesis cell. The presence of long-lived phosphorescence, generated by short-wavelength ultraviolet light, distinguishes these synthetic diamonds from natural material.     

Fast neutron diamond spectrometer

This work is devoted to the development of fast neutron diamond spectrometer intended for the use in diagnostic systems of ITER project. Mathematical code including full model of diamond detector response under neutron irradiation and the problem of the reconstruction of the original neutron spectrum is being developed. Diamond detector response under ²⁴¹Am-Be neutron irradiation has been measured as well as calculated. Acceptable agreement of the original and the reconstructed neutron spectra has been achieved.