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 ZnGa2O4:Cr3+ persistent phosphor by Mg2+ substitution

Ist Teil von

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

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 3+ doped zinc gallate spinel. This disorder was introduced by progressive substitution of Zn 2+ by Mg 2+ 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 3+ in undistorted sites and increases the number of Cr 3+ with neighbouring antisite defects and with neighbouring Cr 3+ 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 3+ spectra with three types of Cr 3+ 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 3+ ions. The effect of Mg substitution on the structure and various types of defects introduced into the structure that affect persistent luminescence was studied.