Abstract

The influence of lithium excess and calcination temperature on the luminescence properties of the LiAl5O8:Eu under VUV excitation was investigated. The presence of both broad bands and sharp peaks in the VUV and X-ray emission spectra suggests the presence of Eu2+, even in absence of reducing atmosphere in the synthesis. The VUV excitation spectra indicated a band gap of 8.5 eV while the UV excited one showed the Eu3+ charge transfer transition starting at 3.9 eV. These values indicate that Eu2+ is stable in this host since its ground state is below the Fermi level of the host (ca. 4.1 eV). The relation between the intensity of Eu2+ and Eu3+ emissions showed that the reduction is favored at higher temperatures and lower Li content, leading to the proposition of a reduction mechanism based on the incorporation of charge compensation defects formed in the aliovalent doping of Eu3+ in Li+ sites.

Full Text
Paper version not known

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 call

Disclaimer: 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.