Abstract
The phosphor powders prepared by calcining mixtures (1:1, 1:2, and 1:3mol ratios) of Eu3+-doped lanthanum(III) hydroxycarbonate (LaCO3OH:Eu3+) and δ-alumina (δ-Al2O3) powders under a mixed gas flow of H2 and N2 exhibited orange (593 and 617nm) and blue (441nm) emission peaks, which were associated with Eu3+-doped lanthanum aluminate (LaAlO3:Eu3+) and Eu2+-doped lanthanum hexaaluminate (La0.827Al11.9O19.09:Eu2+) phosphors, respectively. The relative amount of the latter phosphor increased with increasing reaction temperature and relative amount of δ-Al2O3 in the mixture. The conclusion that the blue emission is not associated with LaAlO3:Eu2+ but La0.827Al11.9O19.09:Eu2+ was supported by the following experimental results: the reduction of LaAlO3:Eu3+ did not give a blue emission; Eu2+ ions occupied more than one site in the host; the line shape and position of the blue emission band were close to those of the single La0.827Al11.9O19.09:Eu2+ phase. No formation of LaAlO3:Eu2+ might be due to the increase in the ionic radius caused by the reduction of Eu3+ to Eu2+.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
