Zul Azhar Zahid Jamal
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Preferred name
Zul Azhar Zahid Jamal
Official Name
Zul Azhar, Zahid Jamal
Alternative Name
Jamal, Z. A. Z.
Jamal, Zul Azhar Zahid
Jamal, Z. A. Zahid
Jamal, ZA
Main Affiliation
Scopus Author ID
18935174100
Researcher ID
FCT-5153-2022

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  • Publication
    Fabrication of calcium phosphate coating on pure magnesium substrate via simple chemical conversion coating: surface properties and corrosion performance evaluations
    ( 2019)
    Mohd Amin Farhan Zaludin
    ;
    Zul Azhar Zahid Jamal
    ;
    Mohd Nazree Derman
    ;
    Mohd Zaheruddin Kasmuin
    The main objective of the current work was to fabricate calcium phosphate (CaP) coating on 99.9% purity magnesium, Mg substrate through simple chemical conversion method and evaluated the surface properties and corrosion performance of the coated substrates. The chemical conversion method was done by immersing the samples inside primary phosphating bath and followed by secondary treatment in alkaline solutions. The coated samples from the primary (PRI) and secondary (SEC) coating treatment were analyzed from morphological, topographical, and phase analysis aspects. The corrosion behaviour of the coatings inside simulated body fluid was assessed by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The PRI and SEC coated were composed of dicalcium phosphate dehydrate (DCPD) and hydroxyapatite (HA), respectively. Both of the coatings improved the corrosion resistance of the Mg substrate. The corrosion potentials, Ecorr of the coated samples becomes nobler compared to the bare substrates. EIS shows that the polarization resistance, Rp is improved about 40 and 2 times fold for PRI and SEC compared to the uncoated samples. Furthermore, PRI shows better corrosion resistance compared to SEC due to lower porosity along with thicker and better coating coverage.
  • Publication
    Nano-silver microcavity enhanced UV GaN light emitter
    ( 2009)
    Ahmed, Naser Mahmoud
    ;
    Zaliman Sauli
    ;
    Uda Hashim
    ;
    Zul Azhar Zahid Jamal
    We report results of measurements that help to clarify the role of silver in the reflection of UV emission light from GaN. A GaN as an active layer was sandwiched between two silver metal reflectors. GaN layer on sapphire showed a photoluminescence (PL) peak around 364 nm and its full width half maximum was about 6.7 nm. Two types of microcavity, were fabricated: half-cavity GaN/sapphire/silver and full-cavity silver/ GaN/sapphire/silver. Photoluminescence measurements showed a two-fold intensity enhancement in half-cavity back mirror. In the full cavity samples, the amplitude of the photoluminescence is enhanced ten times when we used 50 nm silver as a front mirror. A tremendous more than 16-fold enhancement is obtained when silver mirror of 25 nm was used as a front mirror. The increase in the photoluminescence intensity is explained in terms of competition between increasing absorption in the cavity, silver surface plasmon coupling and increasing optical field-enhancement due to resonator.
      3  8
  • Publication
    Frequency dependent electrical properties of ferroelectric Ba₀.₈Sr₀.₂TiO₃ thin film
    ( 1970)
    Ala’eddin A. SAIF
    ;
    Zul Azhar Zahid Jamal
    ;
    Zaliman Sauli
    ;
    Prabakaran A/L Poopalan
    The frequency dependent electrical parameters, such as impedance, electric modulus, dielectric constant and AC conductivity for ferroelectric Baâ‚€.₈Srâ‚€.â‚‚TiO₃ thin film have been investigated within the range of 1 Hz and 106 Hz at room temperature. Z* plane shows two regions corresponding to the bulk mechanism and the distribution of the grain boundaries-electrodes process. M" versus frequency plot reveals a relaxation peak, which is not observed in the ε″ plot and it has been found that this peak is a non-Debye-type. The frequency dependent conductivity plot shows three regions of conduction processes, i. e., a low-frequency region due to DC conduction, a mid-frequency region due to translational hopping motions and a high-frequency region due to localized hopping and/or reorientational motion.http://dx.doi.org/10.5755/j01.ms.17.2.490
      4  18