LASER-ABLATION OF BARIUM-TITANATE CERAMICS PREPARED BY THE CITRIC ROUTE - THE EVOLUTION OF RESIDUAL CARBON CONTENT

The laser-induced ablation mechanism of BaTiO3 ceramics has been follo wed by SEM and EPMA analyses. The evolution of the residual carbon con tent has been studied by C-12(d,p)C-13 nuclear technique under a 10(-9 ) mbar vacuum with laser powers below and above the ablation threshold The residual carbon remains constant for laser powers below the ablat ion threshold and is ejected from the crater formed and partly deposit ed around it when ablation occurs. Immediately after the end of laser ablation, the residual carbon diffuses from the bulk to the surface of the ceramic, leading to high C concentrations in the whole ceramic su rface layer. The chemical form of carbon and its mobility in such cera mics are discussed.