Ti:Al2O3透明多晶陶瓷光谱特性分析

采用传统无压烧结工艺制备出透明性良好的掺Ti氧化铝陶瓷;测定了该陶瓷的吸收光谱、荧光光谱和激发光谱.结果表明,掺Ti氧化铝透明陶瓷样品在Mg与Ti掺入离子的摩尔比(NMg/NTi)较小时,表现出Ti3+离子的490nm特征吸收峰,即2T2→2E跃迁产生的宽带吸收;NMg/NTi较大时,陶瓷样品吸收光谱中不存在Ti3+离子吸收,其250nm处吸收为O2-→Ti4+的转移吸收.掺Ti氧化铝透明陶瓷样品Ti3+离子的发射谱线与单晶的相吻合,同时Ti3+在氧化铝陶瓷中分布很均匀,且Ti3+浓度较高时仍处于未畸变的八面体格位当中.氢气氛下烧结的陶瓷样品因MgO添加剂的存在而在410nm处产生Ti4+离子荧光发射;而280nm、420nm左右的荧光发射分别是由F+和F心造成的.

Spectroscopic Characteristics of Transparent Polycrystailine Ti:Al2O3 Ceramics

Transparent polycrystalline Ti:Al_2O_3 ceramics were fabricated by conventional solid-state pressureless sintering.The absorption,emission and excitation spectra of Ti:Al_2O_3 ceramics were measured.The absorption spectrum of Ti~(3+) ion was observed in the Ti:Al_2O_3 ceramics with low(N_(Mg)/N_(Ti)) mole ratio.Only parasitic UV absorption around 250nm was observed with high mole ratio.The emission spectra of polycrystalline Ti:Al_2O_3 ceramics agreed well with that of single crystal.The heavy doped Ti~(3+) ion was well distributed at the normal octahedral ion site.The emission spectrum caused by isolated Ti~(4+) ion around 410nm was due to the existence of MgO additive in the sample sintered under H_2 atmosphere.However,the emission spectrum around 280nm and 420nm should be caused by F~+ and F centers.