3 documents found, page 1 of 1
Structural and optical studies of Co and Ti implanted sapphire
Alves, E.; Marques, C.; Silva, R.C. da; Monteiro, T.; Soares, J.; McHargue, C.; Ononye, L.C.; Allard, L.F.Single crystals of α-Al2O3 with different orientations were implanted with several fluences of Ti and Co ions. For low fluences both Ti and Co ions are fully incorporated in Al lattice sites and remain stable up to annealing temperatures of 1000 °C. For fluences of 5 × 1016 cm-2 the implanted region becomes completely disordered (amorphous) for samples implanted with Ti while for Co the same condition is achiev...
Luminescence and structural studies of iron implanted α-Al2O3
Monteiro, T.; Boemare, C.; Soares, M.J.; Alves, E.; Marques, C.; McHargue, C.; Ononye, L.C.; Allard, L.F.Transition metal ions (TM) are typically contaminants of growth processes in wide band gap materials. In Al2O3 (Eg ∼ 9 eV) Cr, Fe and Ti are responsible for red, yellow and blue colored sapphire. While the R-lines from Cr3+ have been extensively studied by photoluminescence (PL) the optical characterization of other transition metal ions is less known. In this work we studied by PL, transmission electron micros...
Influence of annealing atmosphere on the behavior of titanium implanted sapphire
Marques, C.; Alves, E.; McHargue, C.; Ononye, L.C.; Monteiro, T.; Soares, J.; Allard, L.F.Sapphire single crystals with (0 0 0 1) and (0 2 2̄ 1) orientations were implanted at room temperature with several fluences of Ti at 150 keV. For low fluences (up to 1 × 1015 Ti+/cm2) the Ti ions are fully incorporated in Al sites of the lattice and remain stable up to temperatures of the order of 1000 °C as revealed by detailed channeling angular scans. The amorphous state is reached after implantation of 5 ×...