Structure and Optical-Lumenescent Characteristics of Mg1 – xZnxGa2O4: Mn2+ Ceramics

Authors A. Luchechko , O. Kravets, O. Tsvetkova

Ivan Franko National University of Lviv, 107, Tarnavskogo st., 79017 Lviv, Ukraine

Issue Volume 9, Year 2017, Number 1
Dates Received 02 November 2016; revised manuscript received 07 February 2017; published online 20 February 2017
Citation A. Luchechko, O. Kravets, O. Tsvetkova, J. Nano- Electron. Phys. 9 No 1, 01003 (2017)
DOI 10.21272/jnep.9(1).01003
PACS Number(s) 61.05.cp, 78.40.Kc, 78.70.En
Keywords Gallates Mg1 – xZnxGa2O4, Spinel, Transition metal ions Mn2+, Solid solution (6) , Optical absorption (3) , Luminescence (24) .
Annotation MgGa2O4, Mg0.5Zn0.5Ga2O4 and ZnGa2O4 ceramics samples doped with Mn2+ ions synthesized via high-temperature solid state reaction method at 1200 C have been investigated. Cubic spinel structure with Fd3m space group has been confirmed by XRD technique in all samples. It was shown that increasing of Zn2+ content leads to increasing of lattice parameter. Elements distribution spectra investigation shows that obtained samples are stoichiometric spinel compounds. Scanning electron microscopy investigations were performed for staring materials powder, surface and cloven of ceramic sample. Crystallite size estimation evaluated with Scherrer's formula are in well agreement with results obtained with scanning electron microscopy. A shoulder related with absorption of charge transfer band from O2– to Mn2+ was found in the region of fundamental absorption edge. Band gaps of ceramic samples were determined from absorption spectra. It is shown, that a grade of Mg2+ cations substitution by Zn2+ cations affects band gap of obtained ceramics. X-ray luminescence investigations were carried out at room and liquid nitrogen temperatures. Three luminescence bands ascribed to matrix, Mn2+ activator ions and Cr3+ uncontrolled impurity were detected. All samples show doubled intensity of matrix luminescence at liquid nitrogen temperature. Luminescence of Mn2+ and Cr3+ ions has recombination nature and slightly dependent on temperature.

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