No abstract

We report on successful preparation of Er 3+ doped transparent alumina (0.1-0.17 at. %) exhibiting visible light photoluminescence using wet shaping method and hot isostatic pressing. The effects of dopant amount, type of doping powder and powder pre-treatment on final microstructure, real in-line transmittance and photoluminescence characteristics were studied.The real in-line transmittance ranged between 28-56 %, depending on processing parameters.The transparency decreased with increased amount of dopant. The decrease is dependent on the type of doping powder and its pre-treatment.The photoluminescence spectra measured in both visible and NIR region showed typical emission bands due to the presence of Er 3+ ions. The decay profiles of the 4 S3/2→ 4 I15/2 transition were fitted with a 2-exponential function, with faster component in the range of 360-700 ns and slower component around 1.6-2.4 μs. The intensity of emissions and lifetime of the 4 S3/2 level decrease significantly with increasing concentration of Er 3+ ions.

No abstract

The Eu 3+-doped transparent aluminas were prepared by wet shaping technique followed by pressure-less sintering and hot isostatic pressing. The effect of dopant amount on microstructure, real in-line transmission (RIT), photoluminescence (PL) properties, hardness and fracture behaviour was studied. The RIT decreased with increasing amount of the dopant. The PL emission spectra of Al2O3:Eu 3+ ceramics exhibited predominant red light emission with the highest intensity (under 394 nm excitation) for material containing 0.125 at.% of Eu 3+ and colour coordinates (0.645, 0.355) comparable with commercial red phosphors. The doping resulted in hardness increase from 26.1 GPa for undoped alumina to 27.6 GPa for Eu-doped sample. The study of fracture surfaces showed predominantly intergranular crack propagation micro-mechanism.

No abstract

No abstract

No abstract

No abstract