Now showing 1 - 3 of 3
  • Publication
    Effect of Sn Doping on the Curie Temperature, Structural, Dielectric and Piezoelectric Properties of Ba0.8Sr0.2Ti1−xSnxO3 Ceramics
    ( 2023-11-01)
    Nasir N.N.
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    ; ;
    Muhsen K.N.D.K.
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    ; ;
    Jumali M.H.H.
    ;
    Jamil N.H.B.
    Ba0.8Sr0.2Ti1−xSnxO3 material with varying Sn concentrations (x = 0, 0.02, 0.04, 0.06, 0.08, and 0.10) was synthesized using the conventional solid-state reaction method. X-ray diffraction (XRD) analysis reveals that as the Sn concentration increases from x = 0 to x = 0.10, the Ba0.8Sr0.2Ti1−xSnxO3 undergoes a structural phase change from tetragonal to cubic. Dielectric analysis of Ba0.8Sr0.2Ti1−xSnxO3 shows a significant drop in Tc, from 65 to 5°C, caused by the replacement of Sn4+ ions with larger ionic radii compared to Ti4+ ions at the B-sites. The composition with x = 0 exhibits the largest dielectric constant due to its enormous spontaneous dipole moments. Conversely, the substitution of Sn in Ba0.8Sr0.2Ti1−xSnxO3 reveals a decrease in the dielectric constant at the B-site structure of perovskite, resulting in a reduced tolerance factor and a decrease in the tetragonality of the sample. However, the pinching effect significantly enhances the dielectric constant of the sample with x = 0.10. Grain size measurements for x = 0 demonstrate a well-distributed grain structure. Additionally, the undoped sample exhibits a higher piezoelectric constant than the Ba0.8Sr0.2Ti1−xSnxO3 samples. According to the piezoelectric constant data, the composition with a tetragonal structure appears to have a greater piezoelectric constant than the cubic structure.
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  • Publication
    Impedance and modulus spectroscopy of polycrystalline Ba0.9995La0.0005TiO3for multilayer ceramic capacitor
    ( 2021-07-21)
    Tiong Yuan Tze
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    ; ;
    Ku Noor Dhaniah Ku Muhsen
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    ;
    Wahab Y.A.
    ;
    Sagadevan S.
    ;
    Sebastian T.
    ;
    Arturo R.L.D.
    Ba0.9995La0.0005TiO3 ceramics prepared via solid-state reaction route was found to be phase pure at the final sintering temperature of 1300°C for 16 hours. The dielectric constant was varied from 1900 to 2800 from 10 Hz to 100 kHz. Impedance spectroscopy is a powerful technique to study the complexities of ceramic materials such as homogeneity and inhomogeneity of materials that being process during production of most electronic materials. An electronic ceramic component can be visualized as a grain, grain boundary and electrode system. Impedance spectroscopy is being widely used to separate out contribution of the bulk and the grain boundary to the overall equivalent circuit models. Fixed frequency plots of dielectric constant versus temperature for Ba0.9995La0.0005TiO3 ceramics shows typical perovskite response with Curie temperature, Tc about 115 °C and fit with the equivalent circuit which contributed by bulk and grain boundary response.
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  • Publication
    Ga 2 O 3 thin films by sol-gel method its optical properties
    Gallium (III) oxide Ga2O3 is emerging in the field of wide bandgap semiconductor for various applications such as solar-blind photodetectors et al. because of its wide bandgap. For this reason, the optical properties of Ga2O3 by sol-gel method are analyzed. Ga2O3 thin films are prepared by spin coating method. The annealing temperature to make α-Ga2O3 is in the range of 450°C-550°C, where after 550°C, β-Ga2O3 is obtained as reported in reviewed works. Therefore, annealing temperatures of samples are set at 500°C, 700°C and 900°C. X-ray diffraction is performed to characterize the structure of the sample. The optical bandgap of Ga2O3 is calculated based on the transmittance value measured from UV-Visible spectrophotometer, which range from 4.8eV to 5.0eV.
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