UPSI Digital Repository (UDRep)
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Total records found : 2 |
Simplified search suggestions : Hafizah Rajaa Shaari |
1 | 2018 Thesis | Synthesis of vanadium based lithium nickel aluminium oxide systems for good performance cathode materials of lithium-ion batteries Hafizah Rajaa Shaari The objectives of this study is to synthesize lithium nickel oxide (LiNiO2) systems doped with vanadium (V) and aluminium (Al) which gives a constant and good discharge capacity for several cycles. Due to that, LiNi1-x-yAlyO2 systems were developed using carbon combustion synthesis (CCS) and solid-state reaction (SSR) method with different proportions ratio of V and Al which are x = 0.1 mole, and 0.3 mole and y = 0.1 mole. The sintering time used was 18 hours for SSR and five hours for CCS at 900°C. The first experiment is to obtain crystalline structure by x-ray diffraction analysis (XRD). The results revealed that the LiNi1-x-yVxAlyO2 are well defined hexagonal crystal system with Rd3m space group. The morphology characterization was done by using scanning electron microscopy (SEM). The SEM image for CCS samples show the presence of hexagonal structures for all the materials and it also was homogeneous. The SEM image of SSR samples showed that the particles distribution were irregul..... 1082 hits |
2 | 2024 Thesis | Optical properties and emission cross-section of neodymium nanoparticles doped tellurite glass coated with graphene oxide/reduced graphene oxide Hafizah Rajaa Shaari This study investigated the optical properties of neodymium nanoparticles (NPs) doped
tellurite glass coated with graphene oxide (GO)/ reduced graphene oxide (rGO). Two series
of glasses were prepared and coated using melt-quenching and spray-coating methods. The
X-ray diffractograms proved the amorphous structure of the glass series. The presence of
non-bridging oxygens in the glass network were proven via FTIR analysis. Meanwhile, the
existence of neodymium nanoparticles in the tellurite glass network were confirmed using
TEM analysis. FESEM and EDX analysis showed the morphologies of GO and rGO on
the glass surface and their chemical elements, respectively. From UV-Vis spectroscopy
analysis, the optical band gaps of ZBTNd (NPs)-GO and ZBTNd (NPs)-rGO were found
in the range 2.355-2.998 eV and 2.770-3.125 eV, respectively. Meanwhile, the refractive
index of ZBTNd (NPs)-GO and ZBTNd (NPs)-rGO were 2.041-2.194 and 2.339-2.657,
respectively. Furthermore, the oxide ion polariz..... 36 hits |