Rozana Aina Maulat Osman
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Preferred name
Rozana Aina Maulat Osman
Official Name
Rozana Aina, Maulat Osman
Alternative Name
Osman, R. A.M.
Osman, A. Rozana
Maulat Osman, Rozana Aina
Osman, Rozana A.M.
Osman, R.
Osman, R. A.Maulat
Main Affiliation
Scopus Author ID
37261764900
Researcher ID
DXB-4277-2022

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  • Publication
    Influence of heating temperature on structure, morphology and electrochemical performance of LiV₃O₈ cathode for lithium-ion batteries application
    (Trans Tech Publications Ltd., 2020)
    Mohamad Izha Ishak
    ;
    Khairel Rafezi Ahmad
    ;
    Rozana Aina Maulat Osman
    ;
    Mohd Sobri Idris
    LiV₃O₈ layered structure was successfully synthesized by a conventional solid-state approach and subsequent heat-treated at 400, 450, 500 and 550 ºC. The samples were characterized by XRD, SEM, TEM, BET. Electrochemical performance of LiV₃O₈ was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge. The results showed that high purity of LiV3O8 with layered structure was formed. The morphology of the samples were mixed between nanorods and nanosheets structure. For electrochemical performance, results showed that LiV₃O₈ heat-treated at 500 ºC performed a highest charge and discharge capacity of 212 and 172 mAh g-1, respectively. From electrochemical performance results made them a good candidate for cathode material for lithium-ion batteries application.
  • Publication
    Facile synthesis of layered LiV₃O₈ nanosheets and their electrochemical performance as cathode materials for Li-Ion batteries
    (Springer, 2020-03)
    Mohamad Izha Ishak
    ;
    Mohd Sobri Idris
    ;
    Rozana Aina Maulat Osman
    ;
    S. M. Hasanaly
    ;
    A. H. Hashim
    ;
    M. F. Rosle
    ;
    Khairel Rafezi Ahmad
    Layered nanosheets of a LiV₃O₈ cathode material were successfully prepared via a modified solid-state synthesis. The morphological changes of the layered nanosheets of the LiV₃O₈ cathode, which resulted from preparation at different temperatures, strongly affected the electrochemical performance of this cathode material. The layered nanosheets of the LiV₃O₈ cathode prepared at 500 °C delivered the highest electrochemical performance with initial charge and discharge capacities of 212 and 175 mAh g−1, respectively, when cycled between 1.5 and 4.0 V versus Li/Li+. The particulate morphology of LiV₃O₈ showed widths in a range of 100-145 nm and lengths between 1.0 and 2.5 µm. The layered nanosheet structure contributed to the increased electrochemical performance of LiV₃O₈ as a cathode material for applications in high-energy lithium-ion batteries.
  • Publication
    Electrical properties of Sn doped SrTiO₃
    (AIP Publishing, 2020-01)
    Muhammad Haniff Fisoldin
    ;
    Mohd Sobri Idris
    ;
    Rozana Aina Maulat Osman
    ;
    Ku Noor Dhaniah Ku Muhsen
    ;
    Zul Azhar Zahid Jamal
    The crystal structure and electrical properties of SrTiO₃ with addition of 50 mol% SnO2 was studied. Samples were prepared using conventional solid-state reaction route. The results indicate that Sn doped SrTiO₃ was single phase with cubic phase and space group Pm-3m after final sintering temparture at 1400°C. Two semicircular arcs clearly observed in Z" versus Z' plots for SrTi0.5Sn0.5O3 semicircles associated with bulk relaxation processes and grain boundary effect. The heterogeneity of sample was observed form Z' and M" spectroscopic plot. The highest dielectric constant is observed at much higher temperature which nearly 2000 at low frequency measurement.
  • Publication
    Colossal permittivity and dielectric behaviour of (Nb₀.₅Fe₀.₅)₀.₁Ti₀.₉O₂ and (Ta₀.₅Fe₀.₅)₀.₁Ti₀.₉O₂ ceramics
    (Springer Nature, 2023)
    Ku Noor Dhaniah Ku Muhsen
    ;
    Rozana Aina Maulat Osman
    ;
    Mohd Sobri Idris
    The influence of pentavalent elements (Nb⁵⁺, Ta⁵⁺) with Fe³⁺ on TiO₂ ceramic were investigated. The (Nb₀.₅Fe₀.₅)₀.₁Ti₀.₉O₂ and (Ta₀.₅Fe₀.₅)₀.₁Ti₀.₉O₂ ceramics have been synthesized and realized that the effect of Nb in the system has developed lattice expansion, although Nb and Ta exhibit similar ionic radii. The colossal permittivity value for (Nb₀.₅Fe₀.₅)₀.₁Ti₀.₉O₂ ceramic is about εr ≥ 104 which is slightly higher than the (Ta₀.₅Fe₀.₅)₀.₁Ti₀.₉O₂ ceramic. According to the dielectric analysis, both ceramics exhibit colossal permittivity below 10³ Hz which contributed by the electron-pinned defect-dipole (EPDD) model. However, the low εr values in the high-frequency region are associated with the internal barrier layer capacitor (IBLC) model. In addition, the grain boundary resistance is far greater than the grain resistivity (Rgb≫ Rg) which confirmed the existence of the IBLC effect by equivalent circuit analysis.
  • Publication
    The effect of cation ordering on the structure, electrical and electronic properties of cubic spinel LiNi₀.₅Mn₁.₅O₄
    ( 2025-01)
    Edi Yasa Ardiansyah
    ;
    Mohd Sobri Idris
    ;
    Rozana Aina Maulat Osman
    ;
    Fahmi Fahmi
    In this paper, we present the investigation of the impact of cation ordering on the structural, electrical, and electronic properties of a cubic spinel LiNi₀.₅Mn₁.₅O₄. Rietveld refinement using X-ray diffraction (XRD) data reveals that LiNi₀.₅Mn₁.₅O₄ annealed at 700 °C adopts a well-ordered atomic arrangement in cubic spinel (SG = P4332). Then, it is transformed to a disordered cubic spinel (SG = Fd-3m) at higher temperatures (> 800 °C). Impedance spectroscopy is employed to evaluate the dielectric and electrical properties in the temperature range of 0 to 25oC within the frequency range between 10 Hz and 100 kHz. The Cole-Cole plot indicates that grain boundaries contribute significantly to electrical conductivity and that bulk resistance decreases with increasing temperature. The AC conductivity analysis shows that the electrical conductivity of well-ordered and disordered cubic spinel LiNi₀.₅Mn₁.₅O₄ exhibits thermal activation and obeys Jonscher's universal power law. Furthermore, the electronic properties of cubic spinel LiNi₀.₅Mn₁.₅O₄ with the space groups of Fd-3m and P4332 are investigated using the density functional theory (DFT) plane-wave method. The electronic analysis of the cubic spinel LiNi₀.₅Mn₁.₅O₄ (SG = Fd-3m) indicates stronger bonding between oxygen and transition metal elements compared to the LiNi₀.₅Mn₁.₅O₄ (SG = P4332) structure. Therefore, LiNi₀.₅Mn₁.₅O₄ with the Fd-3m space group exhibits high structural stability, making it a favourable cathode material for high-voltage rechargeable lithium-ion batteries.
      14  1
  • Publication
    Structural and electrical properties of Barium Titanate (BaTiO3) and Neodymium doped BaTiO3 (Ba0.995Nd0.005TiO3)
    ( 2017)
    Tuan Amirah Tuan Sulong
    ;
    Rozana Aina Maulat Osman
    ;
    Mohd Sobri Idris
    ;
    Zul Azhar Zahid Jamal
    Barium titanate (BaTiO3) and Neodymium (Nd) doped BaTiO3 with composition Ba0.995Nd0.005TiO3 were prepared using conventional solid state reaction method to study the dielectric properties of materials. Pure phase samples were found at final heating temperature of 1400°C for overnight. X-ray diffraction analysis reveals the changes in the lattice parameter and unit cell volume of the pure perovskite tetragonal structure with space group (P4mm). Electrical analysis is carried out to investigate the dielectric properties, conductivity behaviour and dielectric loss of BaTiO3 and Ba0.995Nd0.005TiO3. Ba0.995Nd0.005TiO3 have a broaden dielectric peaks with high permittivity of 8000 and reasonably low loss tan δ which is about 0.004 (1 kHz).
      20  9
  • 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.
    ;
    Rozana Aina Maulat Osman
    ;
    Mohd Sobri Idris
    ;
    Muhsen K.N.D.K.
    ;
    Prabakaran A/L Poopalan
    ;
    Nur Izzati Muhammad Nadzri
    ;
    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.
      1  34
  • Publication
    Impedance and modulus spectroscopy of polycrystalline Ba0.9995La0.0005TiO3for multilayer ceramic capacitor
    ( 2021-07-21)
    Tiong Yuan Tze
    ;
    Rozana Aina Maulat Osman
    ;
    Mohd Sobri Idris
    ;
    Ku Noor Dhaniah Ku Muhsen
    ;
    Nurul Izza Mohd Nor
    ;
    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.
      1  29
  • Publication
    Junction engineering in two-stepped recessed SiGe MOSFETs for high performance application
    ( 2020-01-08)
    Wahab Y.A.
    ;
    Soin N.
    ;
    Naseer M.N.
    ;
    Hussin H.
    ;
    Rozana Aina Maulat Osman
    ;
    Johan M.R.
    ;
    Hamizi N.A.
    ;
    Pivehzhani O.A.
    ;
    Chowdhury Z.Z.
    ;
    Sagadevan S.
    ;
    Thennarasan Sabapathy
    SiGe being one of the most diverse, emerging and richest material for MOSFETs is alluring the scientist due to its unique characteristics like high performance, high surface channel mobility and low threshold voltage as compare to that of silicon MOSFETs. In spite of so much cruciality, the performance of SiGe MOSFETs is being controlled by several factors like resistance and junction depth. These factors urged scientists to not relieve on the traditional methods of junction meteorology to utilize the actual potential and high performance of SiGe MOSFETs in terms of their application. Hence, a paradigm shift in junction engineering is being observed during last few years and discussed. The main focus of this paper is to highlight junction metrologies (ion implantation and annealing) that were tested on SiGe MOSFETs and to propose the most efficient and sustainable technique of junction engineering for high performance applications.
      4  23
  • Publication
    Dielectric and microstructural properties of BaTiO3 and Ba0.9925Er0.0075TiO3 ceramics
    ( 2017)
    Fatin Adila Ismail
    ;
    Rozana Aina Maulat Osman
    ;
    Mohd Sobri Idris
    ;
    Sanna Taking
    ;
    Zul Azhar Zahid Jamal
    BaTiO3 and Ba0.9925Er0.0075TiO3 ceramics were investigated regarding their dielectric and microstructure properties via conventional solid state reaction method. The phase pure samples were obtained when heated at 1400°C for overnight. The effect of Er3+ doped into BaTiO3 on dielectric properties and microstructural properties was investigated for composition of BaTiO3 and Ba0.9925Er0.0075TiO3. The analysis was made by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Impedance Analyzer. The XRD patterns of BaTiO3 and Ba0.9925Er0.0075TiO3 are phase pure and identical with tetragonal perovskite structure with space group of P4mm. The lattice parameters and unit cell volume of BaTiO3 increased by doping with Erbium as the crystallite size decreased. Measurements of dielectric properties were carried out as a function of temperature up to 200°C at different frequencies. Ba0.9925Er0.0075TiO3 exhibit the high value of dielectric constant (ε=6179) at Curie temperature (TC) of 120°C. SEM analysis of BaTiO3 and Ba0.9925Er0.0075TiO3 ceramics showed that the grain sizes of BaTiO3 and Ba0.9925Er0.0075TiO3 were ranged from 3.3µm-7.8µm and 2.2µm-4.7µm respectively.
      1  21