Ammonothermal Synthesis of Novel Nitrides: Case Study on CaGaSiN3
Autor: | Eberhard Schlücker, Oliver Oeckler, Nicolas S. A. Alt, Anna-Carina L. Kimmel, Wolfgang Schnick, Robin Niklaus, Mathias Mallmann, Jonas Häusler, Lukas Neudert |
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Rok vydání: | 2016 |
Předmět: |
Chemistry
Organic Chemistry Doping Intermetallic 02 engineering and technology General Chemistry Crystal structure Nitride 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis 0104 chemical sciences Crystallography Orthorhombic crystal system Isostructural 0210 nano-technology Luminescence Nitriding |
Zdroj: | Chemistry - A European Journal. 23:2583-2590 |
ISSN: | 0947-6539 |
Popis: | The first gallium-containing nitridosilicate CaGa-SiN3 was synthesized in newly developed high-pressure autoclaves using supercritical ammonia as solvent and nitriding agent. The reaction was conducted in an ammonobasic environment starting from intermetallic CaGaSi with NaN3 as a mineralizer. At 770 K, intermediate compounds were obtained, which were subsequently converted to the crystalline nitride at temperatures up to 1070K (70-150 MPa). The impact of other mineralizers (e. g., LiN3, KN3, and CsN3) on the product formation was investigated as well. The crystal structure of CaGaSiN3 was analyzed by powder X-ray diffraction and refined by the Rietveld method. The structural results were further corroborated by transmission electron mi-croscopy, 29SiMAS-NMR, and first-principle DFT calculations. CaGaSiN3 crystallizes in the orthorhombic space group Cmc21 (no. 36) with lattice parameters a= 9.8855(11), b= 5.6595(1), c= 5.0810(1) a, (Z= 4, Rwp= 0.0326), and is isostructural with CaAlSiN3 (CASN). Eu2+ doped samples exhibit red luminescence with an emission maximum of 620 nm and FWHM of 90 nm. Thus, CaGaSiN3: Eu2+ also represents an interesting candidate as a red-emitting material in phosphor-converted light-emitting diodes (pc-LEDs). In addition to the already known substitution of alkaline-earth metals in (Ca, Sr) AlSiN3: Eu2+, inclusion of Ga is a further and promising perspective for luminescence tuning of widely used redemitting CASN type materials. |
Databáze: | OpenAIRE |
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