Synthesis and study of europium doped BaI2 in glass ceramic form

Abstract

Present paper reports an approach to BaI2:Eu2+ glass ceramic fabrication from a powder route. The structural, morphological, luminescent and paramagnetic properties of the materials synthesized this way have been investigated. X-ray diffraction analysis made evidence for the glass ceramics containing BaI2·2H2O and BaI2 inclusions when 50 wt.% of the starting iodide powder had been used in the synthesis process. According to scanning electron microscopy, only two samples demonstrated presence of ceramics particles inside: those with initial mix of 25 and 50 wt.% of the BaI2:Eu2+. Photoluminescence spectra could be measured only in these samples. They were multicomponent as compared to the single band spectrum observed in the BaI2:Eu2+ powder. Altogether this indicates europium distribution over several places with different environments in the materials. BaI2 dissolution in the glass matrix is confirmed further by electron paramagnetic resonance measurements. They have shown that the Eu2+ ions predominantly stay in the glass avoiding ceramic grains. Only negligibly small amount presumably occupies the ceramic part in the sample with the initial 50 wt.% part of the BaI2 powder. The Eu2+ → Eu3+ charge transformation under 442 nm laser light irradiation has been observed in the glass ceramics as well.