Narit Funsueb

Effect of Sintering Condition on Electrical Properties of PLZT Ceramics

Feroelectric lead lanthanum zirconate titanate (PLZT) ceramics 9/70/30 were synthesized by conventional mixed-oxide method via a vibro-milling technique. The effect of sintering temperature and two-stage sintering method on electrical properties of PLZT ceramics was investigated. The ceramic powder was uniaxially pressed in pellets and sintered at the temperatures ranging from 1200 to 1275 °C for 4hrs and two-stage sintering temperature at 1200 °C for 4 hrs. Dielectric, ferroelectric and strain properties of ceramics were characterized by LCR meter, modified Sawyer–Tower Circuit and modified Michelson interferometric technique respectively.

Effect of hybrid doping on dielectric behavior of barium titanate ceramics

ABSTRACT Hybrid-doped BaTiO3 ferroelectric polycrystalline ceramic samples were synthesized by solid state reaction. The concentration of La3+ was fixed 1 mol% while that of Sm3+ varied from 1 to 4 mol%. The effect of the replacement, which can be either lanthanum or samarium, in a cationic site on structural and physical properties of BaTiO3 was investigated. The dielectric permittivity changed significantly with temperature in a wide temperature rang. It was found that the dielectric behavior can be ascribed to the change in defect concentrations in different lattice locations in BaTiO3 structure.

Temperature and induced electric field dependence on the phase transition of 9/70/30, 9/65/35 and 9/60/40 PLZT ceramics

ABSTRACT In this work, Pb0.91La0.09(Zr1–xTix)0.9775O3 ceramics where x = 0.3, 0.35 and 0.4 (the composition near MPB) were prepared by solid solution method. After fabrication process, electrical property was measured by LCR meter. Polarization and induced strain behavior of the samples were investigated by using interferometry technique modified with Sawyer–Tower circuit at various temperatures. The results of dielectric, polarization and induced strain properties were due to the Zr/Ti ratios, which changed their behavior when temperature was varied (30–70 °C). The normal to macro-micro domains to relaxor and paraelectric phase transition was demonstrated which is related to linear or nonlinear increase of polarization and induced strain as a function of applied subswitching electric field.

Structure Properties Relationship of Pb0.92La0.08(Zr0.4Ti0.6)0.98O3 Ceramics

Structure–property relationship has been performed in the lanthanum-modified lead–zirconate–titanate (PLZT) with a lanthanum content 8 and Zr/Ti ratio 40/60. The X-ray diffraction analysis, scanning electron microscopy, and sintering behavior have evidently demonstrated that it is possible to tailor the structural properties of PLZT 8/40/60. Structure of PLZT 8/40/60 had pure perovskite with tetragonal without secondary phase. Tetragonality (c/a) was observed in the range of 1.01093-1.02095. SEM micrographs were shown a development of mean grain size to clarify the development of grain after sintering processing. The result shows that increasing of sintering temperature resulted in mean grain size increasing from 1.70 to 3.08 μm. Ferroelectricity of PLZT ceramics were normal ferroelectric and dielectric constant increased with the increasing sintering temperature.

Temperature Dependence of Electric Field Induced Strain in PLZT 9/65/35 Ceramics

In this study, leadbased ferroelectric ceramics Pb0.91La0.09Zr0.65Ti0.35O3 PLZT (9/65/35) were fabricated by solid solution method. The electrical and mechanical properties were measured by modified Michelson interferometer and Sawyer-Tower circuit to investigate electric field induced strain and polarization (s-P-E) of PLZT (9/65/35) at 30-70 °C. The induced strain and polarization were changed when the temperature was increased indicating the change of spontaneous polarization inside the ferroelectric materials.

Local Structure and Phase Formation of Lead Zinc Niobate Powders by X-Ray Absorption Spectroscopy

This work is aimed at synthesizing lead zinc niobate powders which consist of pyrochlore phases by modified solid-state reaction via a rapid vibro-milling in difference three synthesis routes: mixed oxide precursor (PZN-M) , columbite precuresor (PZN-C) and lead niobate precuresor (PZN-P). It involves the fabrication of PZN powder and study of phase formation and local structural environment of Zn ions by using X-ray Diffraction (XRD) and X-Ray Absorption Spectroscopy (XAS) techniques that compared the amount of pyrochlore phases with perovskite phase.

Effect of Zr/Ti Ratio on Electrical Properties of Pb0.91La0.09(ZrxTi1-x)O3 Ceramics

In this study, Pb0.91La0.09(ZrxTi1-x)O3 ceramics ( x = 0.75, 0.70, 0.65, 0.60, 0.55 and 0.50) have been synthesized by conventional mixed oxide method via a vibro-milling technique. The effect of composition on phase formation and electrical properties of PLZT ceramics was investigated. All compositions of powders were uniaxially pressed in pellets and sintered at the temperatures of 1275°C for 2h. Phase formation, dielectric, ferroelectric strain properties of ceramics were characterized by XRD, LCR meter, modified Sawyer–Tower Circuit and modified Michelson interferometric technique respectively. In this study new materials will be systematically developed based on the material engineering approach (processing vs electrical properties).

Investigation on Structural and Electrical Property of (1-x) PLZT - x PZN Ceramics

In this study, (1-x)Pb0.92La0.08(Zr0.4Ti0.6)O3 - xPb (Zn1/3Nb2/3)O3 (PLZT-PZN, x = 0, 0.05, 0.10, 0.15 0.20 and 0.25) ceramics with pure perovskite were synthesized by mixed oxide synthetic route via a rapid vibro-milling technique. The ceramic pellets were sintered at 1250°C for 4 h. The phase formation and composition was investigated using X-ray diffraction. The dielectric properties of the densified samples were investigated by LCR meter as a function of temperature and frequency. It can be seen that when optimal amount of PZN was added to tetragonal Pb0.92La0.08(Zr0.4Ti0.6)O3 ceramics, the electrical properties were found to be optimal.

Effect of Barium Titanate Additives on Dielectric Property of PLZT Ceramics

Barium titanate (BT) additive in lanthanum modified lead zirconate titanate (PLZT) was used to modify the microstructure and resultant properties of (1-x) PLZT– x BT where x= 0, 0.05, 0.10, 0.15, 0.20 and 0.25. Oxide powders were synthesized by mixed oxide synthetic route via a rapid vibro-milling technique. All of samples were sintered at 1275°C with the soaking time of 4 h. The ceramic samples were investigated for phase formation and evolution, dielectric behavior and ferroelectric properties. Introduction of BT in PLZT lattice resulted in ferroelectric tetragonal-rhombohedral structure, and further increase of BT content resulted in stabilizing the ferroelectric tetragonal perovskite phase. Dielectric behavior and ferroelectric properties were examined as a function of BT content.