Wirunchit, Supamas

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Wirunchit, Supamas
Alternative Name
Wirunchit, S.
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Email
supamas.wi@kmitl.ac.th

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    Item type:Publication,
    Effect of lead nickel niobate substitution on phase transitions of lead zirconate ceramics prepared by the solid state reaction method
    (2008-01-01)
    Wirunchit, S.
    ;
    Laoratanakul, P.
    ;
    Vittayakorn, N.
    The solid solution between the antiferroelectric, PbZrO<inf>3</inf> (PZ), and relaxor ferroelectric, Pb(Ni<inf>1/3</inf>Nb<inf>2/3</inf>)O<inf>3</inf> (PNN), was synthesized by the columbite method. The phase structure and phase transition of Pb(Zn<inf>1-X</inf>(Ni<inf>1/3</inf>Nb<inf>2/3</inf>) <inf>x</inf>O<inf>3</inf> (PZNN), where x = 0.0 ≤ x ≤ 0.50, were investigated. The samples were kept at the calcination temperature of 900°C for 4 h and at the sintering temperature of 1,150°C for 2 h. Phase formation and phase transition of PZNN were investigated by x-ray diffraction (XRD) and thermal analysis, respectively. It was found that the structure of sintered pellets is orthorhombic for 0.0 ≤ x ≤ 0.10, rhombohedral for 0.20 ≤ x ≤ 0.30 and pseudo-cubic for x = 0.5. DSC measurement shows that in the antiferroelectric (AFE) phase - ferroelectric (FE) phase and FE to paraelectric (PE) phase; phase transformation temperatures decrease with increasing PNN concentration. The AFE-FE phase transformation was detected for compositions 0.00 ≤x≤ 0.08. © 2008 Trans Tech Publications, Switzerland.
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    Item type:Publication,
    Perovskite phase formation, phase transformations and electrical properties of lead-nickel niobate - Lead zirconate ceramics
    (2007-12-01)
    Vittayakorn, Naratip
    ;
    Wirunchit, Supamas
    ;
    Trisak, Sakda
    ;
    Muanghlua, Rangsan
    ;
    Niemcharoem, Susasak
    The perovskite structure of lead zirconatelead nickel niobate ceramics, (1-x)PbZrO3-xPb(Ni1/3Nb2/3)O3 (PZ - PNN) with x = 0.0-0.5, were synthesized via the columbite precursor method. The formation of the perovskite phase in the calcined powders has been investigated as a function of calcination conditions by TG-DTA and XRD techniques. The complete solid solutions of perovskite phase of PZ-PNN ceramics were obtained over a wide compositional range. The results showed that the concentration of the PNN phase increased the calcination temperature must be increased in order to obtain phase-pure perovskite. In addition, x-ray diffraction indicated a phase transformation from a orthorhombic to a pseudo-cubic phase when the fraction of PNN was increased. A higher relative permittivity value, as a consequence of the higher PNN concentration, was observed.