BaTi (Si, Ge)_3O_9の相安定性と発光特性

概要

論文の詳細を見る
The BaTiSi_<3-x>Ge_xO_9 crystalline phases were synthesized, and their phase-stability and photoluminescent (PL) properties were investigated. The benitoite and tetragermanate-type phases were crystallized in the range of x=0.75-1.5 and x=2.0-3.0, respectively. It was suggested that Ge^<4+> occupies the octahedral Ti site due to the closeness of each ionic radii. The diffuse-reflection spectra revealed an increase in the oxygen-defect center by substitution of Ge in the crystalline phase. Although the BaTiSi_<2.25>Ge_<0.75>O_9 phase showed an efficient blue PL at room temperature, the PL intensity decreased drastically with the increasing x, and eventually the BaTiGe_3O_9 phase indicated a very weak PL in spite of almost the same structure as benitoite, that is, the absolutely-isolated TiO_6 octahedral unit and the Ge_3O_9 ring. It was suggested that the reduction of the PL intensity in the BaTi (Si, Ge)_3O_9 phase was caused by the increase in the oxygen-defect center.
社団法人日本セラミックス協会の論文
2006-04-01