AgGaS2单晶生长石英安瓿镀碳工艺研究

研究了镀碳工艺参数对碳膜的表面形貌、厚度、碳膜与石英管内壁结合力的影响,发现在气体流量为30～40ml/min, 镀碳温度为1040～1060℃,镀碳时间为30～40min,冷却时间为10～12h的条件下,可获得均匀、致密且结合牢固的碳膜层.用此工艺镀碳的石英安瓿生长出的AgGaS2晶体表面光洁,完整性好,缺陷较少.     

321不锈钢单晶体在3.5％MgCl2水溶液中的再钝化过程

用快速划破技术研究了321不锈钢单晶体在3.5％MgCl₂水溶液中裸体表面上氧化膜的形成过程。裸体表面上首先形成一价金属物吸附层,它使腐蚀电流瞬时降低到接近钝态电流,但吸附层是不稳定的过渡物,很快又转变为氧化物。形成吸附层约为2.5 ms,吸附层转变为氧化膜约为3 ms。形成吸附层的动力学规律为i₁(t)=I°exp(-at),氧化膜生长过程的动力学规律为i₂(t)=J°exp(-bt)。氧化膜生长服从高电场下离子导通规律。     

Charge sharing effect on 600 μm pitch pixelated CZT detector for imaging applications

We are currently investigating the spatial resolution of highly pixelated Cadmium Zinc Telluride （CZT） detector for imaging application. A 20 mm × 20 mm× 5 mm CZT substrate was fabricated with 600 μm pitch pixels （500μm anode pixels with 100 μm gap） and coplanar cathode. Charge sharing between two pixels was studied using collimated a 122 keV gamma ray source. Experiments show a resolution of 125 μm FWHM for double-pixel charge sharing events when the 600 μm pixelated and 5 mm thick CZT detector biased at -1000 V. In addition, we analyzed the energy response of the 600 μm pitch pixelated CZT detector.     

HPHT Synthesis of High-Quality Diamond Single Crystals with Micron Grain Size

High-quality diamond single crystals with micron grain size are synthesized with a new high-pressure and high-temperature （HPHT） synthesis technique in a cubic anvil high pressure apparatus. Morphology of the synthesized diamonds is observed by a scanning electron microscope （SEM）. The samples are characterized using laser Raman spectra. The results show that the new synthesis technique improves the nucleation of diamond greatly, and diamond single crystals with perfect morphology and micron grain size are successfully synthesized, with the average grain size of about 6μm. This work provides a new synthesis technique to implement industrialization of high-quality diamond single crystals with super-fine grain size, and paves the way for future development.