A DOUBLE-TEMPERATURE-GRADIENT TECHNIQUE FOR THE GROWTH OF PURE C60 SINGLE CRYSTALS FROM THE VAPOR PHASE

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.     

C60单晶的汽相生长

报道使用Ｃ₆₀粉末，利用双炉装置，通过闭管汽相法生长Ｃ₆₀单晶的实验及结果。Ｃ₆₀单晶的质量很好，较大单晶的尺寸为０．５ｍｍ×０．６１ｍｍ×１．０ｍｍ。Ｘ射线衍射和电子衍射图的分析得到室温下Ｃ₆₀单晶为ｆｃｃ结构，确定了晶格常数，还进行了Ｒａｍａｎ光谱实验，实验结果表明，热、冷区温度及两者的温度差是影响大尺寸Ｃ₆₀单晶汽相生长的主要因素，对此进行了详细的讨论。 关键词：     

LISICON(锗酸锌锂)单晶的Li~ 离子电导

本文研究了Lisicon(锗酸锌锂)单晶的Li~ 离子电导率。发现各结晶学方向电导率之间的关系为σ_b≤σ_a≤σ_c≤σ_[110],但各向异性不强。晶体中Li含量对电导率有明显的影响,当Li/Zn比率由6.7变到9.2时,300℃a方向电导率由4.3×IO~(-2)Q~(-1)·cm~(-1)增加到1.25×10~(-1)Q~(-1)·cm~(-1),logσT对1/T的曲线显示出三个转变点,分别在～80℃,～140℃和～300℃。电导的激活能分别为0.50—0.58eV(25—80℃),0.92eV(～80—140℃),0.64eV(～140—300℃)和0.36eV(>300℃),极化实验表明单晶的电子电导可以忽略。     

提拉生长铌酸锶钠锂晶体的组分过冷及提高晶体品质的研究

本文采用厚晶体抛光、腐蚀、显微观察的方法研究提拉法生长晶体的组分过冷。在高温偏光下研究了铌酸锶钠锂晶体的结构转变温度。采用最佳的生长和工艺条件克服了铌酸锶钠锂晶体的组分过冷和内部生长条纹,提高了晶体的光学均匀性。 关键词：     

A DOUBLE-TEMPERATURE-GRADIENT TECHNIQUE FOR THE GROWTH OF PURE C60 SINGLE CRYSTALS FROM THE VAPOR PHASE

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.     

LISICON(锗酸锌锂)单晶的Li+离子电导

本文研究了Lisicon(锗酸锌锂)单晶的Li⁺离子电导率。发现各结晶学方向电导率之间的关系为σ_b≤σ_a≤σ_c≤σ_[110],但各向异性不强。晶体中Li含量对电导率有明显的影响,当Li/Zn比率由6.7变到9.2时,300℃a方向电导率由4.3×10^-2Ω^-1·cm^-1增加到1.25×10^-1Ω^-1·cm^-1,logσT对1/T的曲线显示出三个转变点,分别在～80℃,～140℃和～300℃。电导的激活能分别为0.50—0.58eV(25—80℃),0.92eV(～80—140℃),0.64eV(～140—300℃)和0.36eV(>300℃),极化实验表明单晶的电子电导可以忽略。 关键词：