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空间的微重力给晶体生长提供了一个消除自然对流、由纯扩散控制的生长环境,为提高晶体质量创造了条件,引起晶体生长研究人员的关注.中国科学院物理研究所和日本东京大学电子工程系合作,1992年在中国第14颗返回式卫星上成功地生长了一根φ6 mm×30 mm外形完整的GaSb单晶.对空间生长的晶体的研究显示:晶体在空间生长部分无Ⅰ类生长条纹,表明晶体生长时既无自然对流也没有Marangoni对流.位错密度测定表明,晶体在空间生长期间熔体未与坩埚器壁接触时生长的晶体位错密度接近于零,而熔体与坩埚器壁接触后位错密度迅速增高.详细叙述了该晶体的生长和研究,分析了微重力对晶体生长的影响,并对空间晶体生长的发展提出看法. 相似文献
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用水溶液生长晶体的方法生长出了不同掺杂的Sr(NO3)2晶体.用电子探针研究了杂质在晶体中的分布情况.结果表明,杂质在晶体中存在扇形分凝,其中Ba在{100}扇形区的含量大于{111}扇形区,而Pb的分凝情况相反,在{111}扇形区的含量大于{100}扇形区.用高分辨X射线衍射摇摆曲线技术研究了纯的、掺Ba的和掺Pb的Sr(NO3)2晶体的完整性情况,并用X射线衍射动力学理论计算了完整Sr(NO3
关键词:
高分辨X射线衍射
杂质
水溶液晶体生长 相似文献
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Influence of Ba^2+ and Pb^2+ Ions on the Raman Dominating Active Vibronic Mode in Strontium Nitrate Crystals 下载免费PDF全文
The compositions of Sr(NO3)2 crystals grown from an aqueous solution doped with Ba^2 and Pb^2 were characterized by the electron probe microanalysis technique.It was found that Ba^2 is enriched in {100} sectors and Pb^2 in {111} sectors.The Raman spectra of different parts of these crystals at room temperature in the ranges of 1038-1070cm^-1 and 650-1150cm^-1 were investigated.The results indicated that barium and lead shift the Raman dominating peaks to the lower frequency and broaden the full width at half maximum.Furthermore,barium probably degrades the properties of the Sr(NO3)2 Raman shifter while lead is anticipated to improve it. 相似文献
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A DOUBLE-TEMPERATURE-GRADIENT TECHNIQUE FOR THE GROWTH OF PURE C60 SINGLE CRYSTALS FROM THE VAPOR PHASE 总被引:1,自引:0,他引:1 下载免费PDF全文
Pure C60 single crystals were grown by a sublimation-condensation method in an evacuated dosed quartz tube situated in a double-temperature-gradient furnace. Large C60 single crystals, up to a size of 0.6 mm×1.0 mm×2.0 mm with quite smooth and shiny faces, were obtained. X-ray diffraction, electron diffraction and X-ray morphology were carried out and showed that the quality of large C60 single crystals grown by the double-temperature-gradient technique is excellent. In this paper the experimental results of the growth of large C60 single crystals are reported and the morphological and structural characterizations are discussed in detail. 相似文献
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应用X射线三晶衍射对LaAlO3衬底上生长的YBa2Cu3Oy薄膜中的应力水平、存在的主要缺陷,以及薄膜与衬底的失配和取向关系等进行了研究。结果表明,薄膜在衬底上几乎完全松弛,应力很小,薄膜存在较严重的晶格取向差缺陷,这是影响薄膜晶体结构完整性的主要因素。此外,衬底与薄膜在垂直于表面和平行于表面方向都存在取向差。
关键词: 相似文献
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Thin films of ternary compounds CuxInyN and CuxTiyN were grown by magnetron sputtering to improve the thermal stability of Cu3N,a material that decomposes below 300℃,and thus promises many interesting applications in directwriting.The effect of In or Ti incorporation in altering the structure and physical properties of copper nitride was evaluated by characterizing the film structure,surface morphology,and temperature dependence of electrical resistivity.More Ti than In can be accommodated by copper nitride without completely deteriorating the Cu3N lattice.A small amount of In or Ti can improve the crystallinity,and consequently the surface morphology.While the decomposition temperature is rarely influenced by In,the Ti-doped sample,Cu59.31Ti2.64N38.05,shows an X-ray diffraction pattern dominated by characteristic Cu3N peaks,even after annealing at 500℃.Both In and Ti reduce the bandgap of the original Cu3N phase,resulting in a smaller electrical resistivity at room temperature.The samples with more Ti content manifest metal-semiconductor transition when cooled from room temperature down to 50 K.These results can be useful in improving the applicability of copper-nitride-based thin films. 相似文献
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Sterilization of mycete attached on the unearthed silk fabrics by an atmospheric pressure plasma jet 下载免费PDF全文
The sterilization of the simulated unearthed silk fabrics using an atmospheric pressure plasma jet(APPJ) system employing Ar/O_2 or He/O_2 plasma to inactivate the mycete attached on the silk fabrics is reported. The effects of the APPJ characteristics(particularly the gas type and discharge power) on the fabric strength, physical-chemical structures,and sterilizing efficiency were investigated. Experimental results showed that the Ar/O_2 APPJ plasma can inactivate the mycete completely within 4.0 min under a discharge power of 50.0 W. Such an APPJ treatment had negligible impact on the mechanical strength of the fabric and the surface chemical characteristics. Moreover, the Ar ions, O and OH radicals were shown to play important roles on the sterilization of the mycete attached on the unearthed silk fabrics. 相似文献
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