一种仿金刚石膜的研究

Study on Imitation of Diamond Film

针对客户声称的表面覆金刚石膜(DF)的合成立方氧化锆进行常规宝石学检测,结果发现,样品为覆膜合成立方氧化锆,但样品表面的覆膜层硬度低、光滑平整,与多晶金刚石膜的粒状结构及单晶金刚石膜表面定向排列的突起等特征均不相同。为了确定表面覆膜层的成分,采用小角X射线衍射仪、X射线光电子能谱仪和红外光谱仪对样品表面的覆膜层进行了物相分析、化学成分分析及谱学测试。X射线衍射分析表明样品表面的覆膜层属于非晶物相;X射线光电子能谱分析表明样品的膜层主要化学成分为C,F。结合薄膜材料资料分析,初步确定其表面覆膜层可能属于非晶氟化碳(a-C∶F)膜;红外光谱分析结果显示样品表面的膜层所导致的1 068cm-1处的特征峰,进一步验证了X射线衍射分析结论。综合结果表明,该样品表面的覆膜层为非晶氟化碳(a-C∶F)膜,是一种仿金刚石膜。

Diamond film （DF）, consisting of carbon atoms and with structure of diamond, posseses a series of special chemical, physical and optical properties, which is a kind of crys talline material synthesized by chemical vapor deposition method （CVD）. Colourless and transparent diamond film is a hot topic of gemmological diamond materials and notable when people study cubic oxidation-zirconium. How to grow colourless and transparent diamond film on the cubic oxidation-zirconium is a new deceptive technology of diamond imitation. In this paper,authors takes a series of conventional gemmotogical testings and the results show that surface of the sample has dark blue film and its interior is clean with some conchoidal fracture at the edge. The density of the sample is 5.78~5.83 g/cm：~ and refractive index of unfilmed part is above 1.78, which is primarily identified as the synthetic cubic oxidation-zirconium. However, the surface of the sample has low hardness and is smooth, which is elifferent from the structure of polycrystalline diamond film and aligning orientation of singlecrystal diamond film. Therefore, small angle X-ray diffraction spectrometer and infrared spectrometer are used in physical, chemical and spectroscopic testings to analyze the sample and determine the chemical composition of the surface film. X-ray diffraction analysis reveals that the surface film is amorphous phase and the result of X-ray photoelectron spectrometer shows that the film primarily consists of element C and F. Combining with the film litera- ture, we can confirm that the film is fluorinated amorphous carbon （a-C ： F） Films. Region during 950 -1 250 cm-1 of infrared spectra is analyzed by ORIGIN software of gaussian func- tion. Six peaks are found, such as stretching vibration of CF （1 030,1 068 cm -1）, strelching vibration of CF2（1 090,1 160,1 220 cm-1）, stretching vibration of CF3（980 cm -1）, which confirms further that the surface film is a C ： F film.