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The influence of irradiation induced damage on the transport of implanted species in poly and single crystalline silicon carbide is investigated. For this purpose published diffusion results of strontium, silver, iodine and cesium are compared with the associated evolution of defect profiles determined by α-particle channelling in a backscattering geometry. Strong diffusion takes place in the amorphized surface layer of room temperature implanted 6H-SiC during annealing at 1100 °C, which drops below the detection limit of 10 -21 m 2 s -1 as soon as re-crystallization is completed. Diffusion in samples implanted above the critical amorphization temperature is only observed when simultaneously a significant reduction of defect density occurs. No diffusion into the undamaged bulk is detected at temperatures up to 1500 °C. The observed diffusion behaviour is explained by a defect related trapping and release mechanism. Normal grain boundary diffusion of silver and iodine occurs in CVD-SiC.

ZnAl 2 O 4 nano-powders have been successfully prepared via citrate sol-gel technique. All powder samples were annealed at 600 o C for 1, 2, and 3 h. Thermogravimetric analysis (TGA) confirmed that the minimum annealing temperature of crystallization is ~ 400 °C. Fourier Transform Infrared (FTIR) results showed a series of absorption peaks in the range of 810-4000 cm-1. The X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) results showed that the prepared nano-crystals consists of the mixture of both cubic (ZnAl 2 O 4) and hexagonal (ZnO) structures. Ultra violet visible (UV-vis) spectroscopy revealed that the annealing time (AT) influences the band gap of the prepared phosphor materials. When the 2 samples were excited at 275 nm, two emission peaks at 428 nm (violet) and 561 nm (green-yellow) were observed and they are attributed to the defects levels within the ZnO and ZnAl 2 O 4 band gaps. The Commission Internationale de l'Elcairage (CIE) colour coordinates confirmed that all the prepared samples exhibit the violet emission and varying the AT does not influence the emission colour.