Liang Zhongzhu

Effects of NaN3 Added in Fe?C System on Inclusion and Impurity of Diamond Synthesized at High Pressure and High Temperature

Effects of NaN3 added in Fe—C system to synthesize nitric diamond at high pressure and high temperature are investigated. Diamond crystals with high nitrogen concentration are synthesized by the system of Fe—C and NaN3 additive at pressure 5.8 GPa and at temperatures 1750–1780K for 15 min. The synthetic diamond crystals have a cubo-octahedral or octahedral shape with yellowish green or green colour. Some disfigurements are observed on the surfaces of most diamond crystals. The composition and content of inclusions formed by iron in diamond are changed and iron nitride is detected in diamond crystals synthesized with Fe–C–NaN3 additive. As the amount of NaN3 additive increases, Fe3 C decreases and iron nitride increases with α-Fe being nearly constant. Moreover, the nitrogen concentrations in diamond crystals synthesized with 1.5wt% NaN3 additive is up to 2250 ppm in substitutional form.

Radiometer Chips for Measuring Solar Irradiance

The solar irradiance measuring is very important for forecasting long-term movement of the climate in the earth.To meet the demands of high performance and microminiaturization of solar irradiance measuring instrument,study of micro device of absolute radiometer is an important future research direction of solar radiation detection.The present research of several typical solar radiometer devices was introduced in this paper.Especially,several thermoelectricity solar radiometer devices in common use were described,and their features were analyzed and compared.

Formation of mixture of A and C centres in diamond synthesized with Fe90Ni10-C-high-content additive NaN3 by HPHT

Very rich nitrogen concentration with the dominant C centres and some A centres are found in diamonds grown from a Fe90Ni10-C-high-content NaN3 additive system. The concentrations of C centres rapidly increase with increasing content of NaN3 additive, while the concentrations of A centres increase slowly. The total nitrogen concentration tends to increase rapidly with increasing content of NaN3 additive when the content of NaN3 is below 0.7 wt%. However, the total concentration of nitrogen in the diamonds increases slowly when the content of NaN3 is further increased up to 1.0 wt%, and the total nitrogen average concentration are calculated to be around 2230 ppm for most of the analysed synthetic diamonds. Furthermore, the nitrogen impurities in different crystal sectors of the diamonds are inhomogeneously distributed. The nitrogen impurities in the diamonds in [111] zones are incorporated more easily than that in [100].