In this work, excellent property infrared (IR) window composite materials was obtained by inorganic-organic compound method. Scanning Electron Microscopy (SEM) observation found that inorganic particles were distributed uniformly in the organic matrix, and good combination between inorganic and organic phase were obtained. The measurement of vitrification point showed that glass temperature of composite materials were higher than that of pure plastic matrix, so the temperature range of application of this kind of composite materials was expanded and its transmittivity was about 80% when wave length was before 30μm.
In this work, the reason of flat interface crystal growth was analyzed and rational technological parameters were desigend and high quality sodium bismuth tungstate single crystal of 45mm in diameter and 35mm in length was grown by Czochralski method. X-ray diffraction spectra showed that the NBW single crystal had cubic system and the space group was I41/a; Transmission spectra of NBW indicated that its anti-radiation damaging capability was strong; Its emission spectra analysis showed that the emission peak was in the range of visible light--green light wave band.
The PWO crystal was grown by Cz method. We found the cause of crystal cracking was as follows: lateral crack; longitudinal length crack; along the cleaveage place crack; random fracture. Structure analysis shows that structure stress which cause the random fracture can be decreased through select high pure raw material and perfect sub-crystal, and main factor of crystal cracking is caused by thermal stress. Through a lot of experiments we have known that crystal cracking of thermal stress included not only along cleavage place crack but also lateral stratum crack and longitudinal length crack which was caused by dissimilar coefficient of expansion in all directions. During designing stable temperature field and selecting rational technology parameters and annealing process, perfect crystal was grown.
In this work, YVO4 crystal with excellent property was grown by Czochralski method when rational growing parameters were designed; the result of TG-DTA analysis showed that the thermal stability of YVO4 crystal was good, and the result of IR spectrum testing showed that YVO4 crystal was a kind of crystal with wide transparence area and good optical property.
In this paper, Cz growth of silicon single crystal in a magnetic field was studied with numerical simulation method. The results of numerical simulation showed that convection of melt could be controlled when the magnetic field was added, moreover, forced convection was controlled much larger than natural convection. The oxygen concentration of the interface would decrease with the strengthening of the magnetic field intensity, but the temperature field of the melt did not change with the strenghtening of the magnetic field.
Nanocrystalline CeO2 of different sizes were prepared by calcining CeO2modify with oleic acid at different calcination temperatures, TEM analysis indicated that nanocrystalline CeO2 was spherical in shape.The average sizes and relative density of nanocrystalline CeO2 increased with the increas ofcalcination temperature .XRD patterns showed that the synthesized CeO2 was cLibic system and space group was O5H?FM 3M when calcination temperature was in the range of450-900°C.