Browsing by Author "Jong Wah, JW"
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- ItemDielectric properties and photoluminescence of diatomaceous silicas(Australian Institute of Physics, 2005-01-31) Jong Wah, JW; Ferris, JM; Wintrebert-Fouquet, M; Butcher, KSASilica shells produced by diatoms have been studied to investigate their potential for applications in electronic and photonic devices due to their dielectric and photoluminescent properties. Dielectric measurements for low (1k-1MHz) and high (∼1GHz) frequencies were performed on processed diatomaceous earth samples and compared with measurements for artificial porous silica samples. Photoluminescence spectra for a sample of freshwater benthic diatoms were obtained and compared with silica spectra. The ratio of the 3.2eV photoluminescence peak compared to a peak at ∼2.20eV is smaller than for pure fused silica, and there is evidence of extra shoulder peak near 2.2eV for diatogenic silica. © 2005 Australian Institute of Physics.
- ItemA luminescence study of porous diatoms(European Materials Research Society, 2004-05) Butcher, KSA; Ferris, JM; Phillips, MR; Wintrebert-Fouquet, M; Jong Wah, JW; Jovanovic, N; Vyverman, W; Chepurnov, VA
- ItemLuminescence study of porous diatoms(Elsevier, 2005-12) Butcher, KSA; Ferris, JM; Phillips, MR; Wintrebert-Fouquet, M; Jong Wah, JW; Jovanovic, N; Vyverman, W; Chepurnov, VAThe cathodoluminescent and photoluminescent properties of the nanoporous silica frustules of various diatom strains and of natural diatom samples are presented. The spectra are observed to be similar to that of pure silica glass and the phenology is therefore believed to also be somewhat similar. A strong U-V-blue luminescence peak is commonly observed as well as a yellow peak at 2.15 eV For the more heavily silicified field-collected freshwater benthic samples, a strong red peak at 1.95 eV is also observed. The 2.15 eV peak is also more strongly evident for the field-collected samples. The U-V-blue peak is related to common silica defect structure but cathodoluminescent microanalysis shows that this emission is highly localized in the diatom samples. © 2005, Elsevier Ltd.