Optical properties of La<subscript>2</subscript>CuO<subscript>4</subscript> and La<subscript>2−x</subscript>Ca<subscript>x</subscript>CuO<subscript>4</subscript> crystallites in UV–vis–NIR region synthesized by sol–gel process
In: Materials Characterization, Jg. 64 (2012-02-01), S. 36-42
Online
academicJournal
Zugriff:
Abstract: La2CuO4 and La2−xCaxCuO4 crystallites were prepared via a simple sol–gel process. The as-prepared La2CuO4 and La2−xCaxCuO4 crystallites were characterized by X-ray diffraction, transmission electron microscope and UV–vis–NIR spectra. Results show that the grain size of La2CuO4 crystallites increases with the increase of heat treatment temperature from 600°C to 800°C. Optical properties show that La2CuO4 crystallites have broad absorption both in the UV–vis region and in the NIR region. The band gap of the as-prepared crystallites decreases from 1.367eV to 1.284eV with the increase of calcination temperature from 600°C to 800°C. In the series of La2−xCaxCuO4 compounds (x=0.05, 0.08, 0.10, 0.12, 0.15 and 0.20), all of the samples exhibit an orthogonal crystal structure and the solubility limit of Ca2+ in La2CuO4 is within the range of x=0.12–0.15. In the whole UV–vis–NIR region, La2−xCaxCuO4 crystallites exhibit a broad absorption and the corresponding band gap first increases and then decreases with increasing of Ca2+ content. [Copyright &y& Elsevier]
Titel: |
Optical properties of La<subscript>2</subscript>CuO<subscript>4</subscript> and La<subscript>2−x</subscript>Ca<subscript>x</subscript>CuO<subscript>4</subscript> crystallites in UV–vis–NIR region synthesized by sol–gel process
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Autor/in / Beteiligte Person: | Li, Yifeng ; Huang, Jianfeng ; Cao, Liyun ; Wu, Jianpeng ; Fei, Jie |
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Zeitschrift: | Materials Characterization, Jg. 64 (2012-02-01), S. 36-42 |
Veröffentlichung: | 2012 |
Medientyp: | academicJournal |
ISSN: | 1044-5803 (print) |
DOI: | 10.1016/j.matchar.2011.11.015 |
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