Growth and Optical Properties of Partially Transparent Eu Doped CaF2 ceramic.

Partially transparent ceramic of 2 at.% Eu doped CaF₂ have been grown preferentially towards [111] direction. For this purpose, Eu doped CaF₂ nanoparticles (size~12 nm) obtained by a low temperature solution growth method has been pressed at 1000°C under vacuum. The preferentially grown ceramic shows 15% transparency within the visible range of spectrum. As confirmed by the X-ray diffraction result, the hot pressed ceramic exhibits reduced lattice volume than the nanopowder. It indicates Eu³⁺ as the dominant substituting ions at the Ca²⁺ sites of CaF₂ lattice in the hot pressed ceramic material. It is corroborated by the photoluminescence results of hot pressed ceramic which shows strong red emission corresponding to Eu³⁺ sites. However, photoluminescence of nanopowder exhibits intense peak in the blue region of the spectrum which is characteristics of Eu²⁺ sites. [ABSTRACT FROM AUTHOR]