Papers by Author: Ezza Syuhada Sazali

Abstract: This presentation provides a panoramic overview of the recent progress in nanoglass plasmonics, challenges, excitement, applied interests and the future promises. Enhanced optical properties of rare earth (RE) doped glasses for sundry applications are current challenges in materials science and technology. Nanoparticles (NPs) dispersed up-converted (UC) glasses seem to be the ideal candidates in terms of both efficiency and large area coverage provided the absorption cross-section be enhanced. The glasses containing gold NPs (AuNPs) and silver NPs (AgNPs) doped with optimum concentration of RE ions are of particular interest to us. We report the influence of embedded NPs on the luminescence and absorbance characteristics of RE ions doped tellurite glass prepared by melt-quenching method. The absorption and emission spectra displays several prominent peaks corresponding to the transitions from the ground state to the excited states of RE ion. The observed efficient enhancement of up-conversion emissions and absorbance in the entire visible region is attributed to strong localized electric field in vicinity of NPs. Improvements of radiative emissions suggests that the proposed glasses are potential for the development of solid state lasers, color displays and nanophotonic devices.

Abstract: Glass samples of composition 79TeO₂ – 15PbO – 5PbCl₂ – 1Er₂O₃ – (x)AuCl₃ with (0.0 ≤ x ≤ 0.1 mol%) were successfully synthesized by using melt-quenching technique. The impacts of gold nanoparticles (GNPs) concentration in stimulating the ligand field interaction inside the erbium-tellurite glass network were inspected. Amorphous nature of the sample was confirmed through XRD pattern. TEM images display the existence of GNPs with average diameter ~1.24 nm. Optical absorption spectra were recorded in the UV-Visible range. The absorption displays several prominent peaks corresponding to the transitions from the ground state to the excited states of Er³⁺ ion. The compositional dependence of the ligand parameters in terms of crystal field strength and Racah parameter were determined.

Abstract: . The study of the crystallization kinetics of rare-earth doped glass stimulated much interest especially for crystallization process. In this work transparent Eu2O3 doped glasses with composition TeO2 - Na2O – MgO were prepared using conventional melt-quenching technique. The amorphous nature of glass was confirmed using X-ray diffraction method. The influence of Eu3+ content on the crystallization kinetics of the glass such as activation energy (Ea) was thoroughly evaluated under non-isothermal conditions using DTA. The crystallization kinetic at different heating rate from 5 °C min-1 to 25 °C min-1 at different crystallization temperature (Tp) were examined and verified using Ozawa method. The result showed that the activation energy (Ea) was decreased with the increasing of the dopant concentration from 319.8 eV to 93.5 eV.