Tunable optical properties of some rare earth elements-doped mayenite Ca₁₂Al₁₄O₃₃ nanopowders elaborated by oxalate precursor route

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• 作者：Mohamed M. Rashad ; Ahmed G. Mostafa ; Bonex W. Mwakikunga…
• 刊名：Applied Physics A
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：123
• 期：1
• 全文大小：
• 刊物类别：Physics and Astronomy
• 刊物主题：Condensed Matter Physics; Optical and Electronic Materials; Nanotechnology; Characterization and Evaluation of Materials; Surfaces and Interfaces, Thin Films; Operating Procedures, Materials Treatment
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-0630
• 卷排序：123

文摘

Rare earth (RE) ions-doped mayenite Ca₁₂Al_14−xRE_xO₃₃ nanopowders (where RE = La and Gd and x = 0–1.0) were synthesized using the oxalate precursor technique. The as-prepared precursors were calcined at 800 °C for 2 h. Obviously, all RE-doped Ca₁₂Al_14−xRE_xO₃₃ possessed a well-crystalline cubic mayenite phase till RE content of 0.8. The crystallo-chemical aspects including crystallite size, lattice parameters, theoretical X-ray density and bulk density were robustly on RE nature and ratio. The microstructure and the average grain size were significantly influenced by the RE kind and content. The high transparency of Ca₁₂Al_14−xRE_xO₃₃ over 80% was found to be evinced in the visible wavelength range of 400–800 nm. Besides, the incorporation of RE cation minimized the direct band gap energy from 4.42 eV for pure mayenite to 3.85 and 3.59 eV with x value 1.0 of La3+ and Gd3+ ions. The photoluminescence spectra of pure mayenite nanoparticles showed that the band edge emission (λ_exc = 248 nm) with an intense visible emission band at 360 nm was detected. Otherwise, the band edge emission showed a slight shift toward short wavelength due to the substitution Al3+ by RE3+ ions. Such results open a new avenue for application of mayenite as a good candidate for transparent low-temperature electron conductor for optoelectronics applications.