Details

Autor(en) / Beteiligte

• Basavaraju, Neelima
• Priolkar, Kaustubh R
• Bessière, Aurélie
• Sharma, Suchinder K
• Gourier, Didier
• Binet, Laurent
• Viana, Bruno
• Emura, Shuichi

Titel

Controlling disorder in the ZnGa 2 O 4 :Cr 3+ persistent phosphor by Mg 2+ substitution

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2017, Vol.19 (2), p.1369-1377

Ort / Verlag

England: Royal Society of Chemistry

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We have studied in this work the effect of increasing structural disorder on the persistent luminescence of a Cr doped zinc gallate spinel. This disorder was introduced by progressive substitution of Zn by Mg ions, and was studied by photoluminescence, X-ray diffraction, extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES) and electron paramagnetic resonance (EPR) spectroscopy. It was found that increasing the Mg/Zn substitution decreases the number of Cr in undistorted sites and increases the number of Cr with neighbouring antisite defects and with neighbouring Cr ions (referred to as Cr clusters), which in turn decreases the intensity of persistent luminescence. Both XANES and EPR spectra could be simulated by a linear combination of Cr spectra with three types of Cr environments. The increasing disorder was found to be correlated with a decrease of the average Cr-O bond length and a decrease of crystal field strength experienced by Cr ions.