Optical properties and thermal stability of germanium oxide (GeO2) nanocrystals with α-quartz structure
Optical properties and thermal stability of germanium oxide (GeO2) nanocrystals with α-quartz structure
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DOI：
10.1016/j.mseb.2010.03.060
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发表时间：
2010-10-25
影响因子：
3.6
通讯作者：
Atuchin, V. V.
中科院分区：
文献类型：
--
作者：
Ramana, C. V.;Carbajal-Franco, G.;Atuchin, V. V.
二氧化锗（GeO2）晶体是通过化学沉淀法在相对较低的温度（100℃）下制备的。通过研究其微观结构、光学性质和热稳定性来表征生长的晶体。结果表明，生长的GeO2晶体呈现a-石英型晶体结构。从 XRD 获得的晶格参数为 a = 4.987(4) 埃和 c = 5.652(5) 埃。电子显微镜分析表明使用本方法生长的 GeO2 晶体具有高结构质量。光吸收测量表明直接带隙为 5.72 eV，没有任何由局部或缺陷态产生的附加能带。热重测量表明生长的 GeO2 纳米晶体的温度稳定性。对具有 α-石英型晶体结构的 GeO2 晶体进行显微分析并结合能量色散 X 射线光谱，表明其化学成分在 400 摄氏度以下保持稳定。GeO2 晶体的表面形貌。然而，发现随着温度的升高而变化。 (C) 2010 Elsevier B.V. 保留所有权利。
Germanium dioxide (GeO2) crystals were prepared by a chemical precipitation method at a relatively low-temperature (100 degrees C). The grown crystals were characterized by studying their microstructure, optical properties and thermal stability. The results indicate that the grown GeO2 crystals exhibit a-quartz type crystal structure. The lattice parameters obtained from XRD were a = 4.987(4)angstrom and c = 5.652(5)angstrom. Electron microscopy analysis indicates a high structural quality of GeO2 crystals grown using the present approach. Optical absorption measurements indicate a direct bandgap of 5.72 eV without any additional bands arising from localized or defect states. Thermogravimetric measurements indicate the temperature stability of the grown GeO2 nanocrystals. Microscopic analysis coupled with energy dispersive X-ray spectroscopy of the GeO2 crystals with alpha-quartz type crystal structure indicates their stability in chemical composition up to a temperature of 400 degrees C. The surface morphology of GeO2 crystals. however, found to be changing with the increase in temperature. (C) 2010 Elsevier B.V. All rights reserved.