Optical and Structural Properties of Zn2TiO4:Mn2+

Autor: N. Cella, I. C. S. Carvalho, Alexandre R. Camara, S.S. Pedro, Lilian P. Sosman, A. López
Rok vydání: 2017
Předmět:
Zdroj: Journal of Electronic Materials. 46:6848-6855
ISSN: 1543-186X
0361-5235
DOI: 10.1007/s11664-017-5742-z
Popis: Polycrystalline Zn2TiO4 samples with Mn2+ doping level of 0%, 0.1%, 1.0%, and 5.0% have been produced by conventional solid-state method and their optical and structural properties investigated. Rietveld refinement of x-ray diffraction patterns revealed the formed phases and the crystallographic parameters. The chemical composition was obtained by x-ray fluorescence measurements. The optical properties were studied by photoluminescence, excitation, reflectance, and photoacoustic spectroscopy. All measurements were performed at room temperature. The photoluminescence spectrum of the pure sample (0% Mn2+) showed a band in the red region associated with Zn2TiO4, while the sample with 0.1% Mn2+ exhibited two bands, in the green and red spectral regions, assigned to Mn2+ ions at tetrahedral and octahedral sites. No emission was observed for the samples with 1.0% or 5.0% Mn2+. The excitation results for the sample with 0.1% Mn2+ ions showed characteristic peaks of Mn2+ transitions. Tanabe–Sugano theory was used to obtain the crystal field Dq, B, and C Racah parameters from the energy peak positions in the excitation spectrum of the sample with 0.1% Mn2+. Photoacoustic measurements revealed a broad band, characteristic of semiconductor materials, hiding the Mn2+ transitions.
Databáze: OpenAIRE
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