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Journal ArticleDOI

Temperature Dependence of Energy Storage Density and Differential Permittivity and Bandgap Study of Relaxor (Pb,La)Zr0.65Ti0.35O3

30 Dec 2019-Integrated Ferroelectrics (Taylor & Francis)-Vol. 202, Iss: 1, pp 153-162
TL;DR: In this paper, the diffusivity values of Pb(1-3x/2)LaxZr0.65Ti0.35O3 (x = 6, 7, 8, 8 and 9%) were obtained.
Abstract: Pb(1-3x/2)LaxZr0.65Ti0.35O3 (x = 6, 7, 8 and 9%) show diffusivity values as 1.55, 1.72, 1.94 and 2.18, respectively. The differential permittivity strongly depends on temperature and electric field...
Citations
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Journal ArticleDOI
TL;DR: In this paper, an ultrahigh energy storage density (W) was achieved in the Ba0.3Sr0.7Zr 0.18Ti0.82O3 (BSZT) relaxor ferroelectric thin films with the help of an ultrathin Ca0.8O1.8 (CSZ) artificial dead layer.

33 citations

Journal ArticleDOI
07 Dec 2020-Energies
TL;DR: In this article, a high-energy ball-milling technique was used to synthesize (Pb0.92La0.08) (Zr0.60Ti0.40) O3 (PLZT 8/60/40) ceramics for microwave sintering at different temperatures from 900 °C to 1200 °C.
Abstract: In this study, (Pb0.92La0.08) (Zr0.60Ti0.40) O3 (PLZT 8/60/40) ceramics were synthesized using a high-energy ball-milling technique followed by microwave sintering at different temperatures from 900 °C to 1200 °C. The optimal microwave sintering temperature for the PLZT 8/60/40 ceramics was found to be 1150 °C, which is relatively low compared with conventional sintering temperature. The sintered ceramics show the pure perovskite phase, uniform grain microstructure (1.2 µm) and high density (~99.5%). The polarization vs. electric field (P-E) hysteresis curves were used to investigate the ferroelectric and energy storage properties. The switching characteristic in P-E loops and occurrence of domain switching current in current vs. electric field (I-E) loops confirms their ferroelectric nature. The PLZT ceramics, which were sintered at 1150 °C, show the highest remnant polarization (Pr) of ~32.18 μC/cm2 and domain switching current (Imax) of ~0.91 mA with a low coercive field (Ec) of ~10.17 kV/cm. The bipolar and unipolar strain vs. electric field (S-E) hysteresis loops were also measured and the highest unipolar strain was found to be ~0.26% for the PLZT ceramics sintered at 1150 °C. The unipolar S-E curves were used to derive the piezoelectric coefficient (d33~495 pm/V) and a strain hysteresis loss (~5.8%).

5 citations

References
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Journal ArticleDOI
TL;DR: In this paper, the Hartree-Fock theory was applied to the PbZr0.53Ti0.47O3 (PZT) and the results showed the outward atomic displacements with respect to the La impurity within the defective region and also the increase of covalent nature in the chemical bonding of the material.
Abstract: Lanthanum-modified Pb(Zr,Ti)O3 (PZT) crystals have been investigated applying a quantum-mechanical approach based on the Hartree–Fock theory. A morphotropic phase boundary (MPB), PbZr0.53Ti0.47O3, of the crystal was considered throughout the study. The obtained results show the outward atomic displacements with respect to the La impurity within the defective region and also the increase of covalent nature in the chemical bonding of the material. These outcomes are discussed and analyzed in light of the available experimental data. The occurrence of Jahn–Teller self-trapped electron polarons is predicted in the present report.

21 citations


"Temperature Dependence of Energy St..." refers background in this paper

  • ...In a quantum mechanical approach, Stashans and Maldonado explained, how the outward atomic displacements with respect to the La impurity within the defective region in PZT causes changes in properties [32]....

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Journal ArticleDOI
TL;DR: In this article, the temperature dependence of the remnant dielectric polarization, PR(T), effective birefringence parameter, Δn¯(T) of hot-pressed ferroelectric 8/65/35 lead zirconate‐lead titanate-lanthanum oxide (PLZT) has been investigated.
Abstract: The temperature dependence of the remnant dielectric polarization, PR(T), effective birefringence parameter, Δn¯(T), of hot‐pressed ferroelectric 8/65/35 lead zirconate‐lead titanate‐lanthanum oxide (PLZT) has been investigated. The material exhibits relaxor behavior and a diffuse phase transition in the neighborhood of 102 to 109 °C. The PR(T) and Δn¯(T), however, dramatically decrease at temperatures distinctly lower than the diffuse phase transition temperature region. A ferroelectric domain alignment in poled samples, and a thermally influenced disalignment is proposed in order to account for the additional observed behavior. A mechanism based upon grain‐boundary heterogeneities is suggested. Differential thermal analysis data are consistent with a domain disalignment scheme.

20 citations


"Temperature Dependence of Energy St..." refers background in this paper

  • ...PLZT (8/65/35) is at the morphotropic phase boundary between rhombohedral and tetragonal structures [1] where increasing La content takes it towards cubic structure [6]....

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Journal ArticleDOI
TL;DR: In this paper, x-ray analysis clearly shows the formation of a single rhombohedral phase in Fe modified Pb0.92La0.08(Zr0.65Ti0.35)O3 (PLZT).
Abstract: Fe modified Pb0.92La0.08(Zr0.65Ti0.35)O3 (PLZT) was prepared by the conventional method based on the solid state reaction of mixed oxides. The x-ray analysis clearly shows the formation of a PLZT single rhombohedral phase. The crystallite size calculated from Sherrer's equation and the grain size determined from microstructures were found to decrease with Fe doping up to 4%. Calculations carried out for the peak intensity of the x-ray diffraction analysis suggest that Fe occupied the A site up to 4% doping and beyond that it occupied both A and B sites in the ABO3 perovskite structure. Dielectric and pyroelectric measurements show a peak at around the Curie transition temperature. The width of the peaks was found to increase with Fe doping along with decreasing peak dielectric and pyroelectric maxima up to 4%. The P–E loop measurements of PLZT samples with Fe doping up to 6% have shown saturated single loops. Pr and EC from the P–E loop were found to increase with increasing applied field and reached saturation at higher applied fields (25 kV cm−1). However, 8% and 10% Fe doped PLZT have shown double unsaturated hysteresis loops. This anti-ferroelectric phase in Fe doped PLZT samples beyond 8% doping is expected to be due to the occupation of Fe in the B site replacing the Ti atom in the ABO3 perovskite structure.

20 citations

Journal ArticleDOI
TL;DR: In this article, the effect of simultaneous doping of donor (Nb) and acceptor (Fe) in PLZT (Pb0.97La0.02Zr0.52Ti0.48O3) is reported.
Abstract: The studies on the effect of simultaneous doping of donor (Nb) and acceptor (Fe) (0–8 at.% of each dopant) in PLZT (Pb0.97La0.02Zr0.52Ti0.48O3), on the dielectric response, ac conductivity and ferroelectricity are reported in this article. It is observed that the value of dielectric constant decreases, dielectric loss increases (moderately) and coercive field increases upon doping of Nb and Fe together. These indicate a hardening like effect as a result of the donor–acceptor co-doping. The ferroelectric to paraelectric phase transition occurs at lower temperatures for higher doping concentrations. For undoped PLZT the Curie temperature is around 353 °C which shifts to 305 °C for 8% Nb–Fe co-doped PLZT. Microstructure studies on the surface, as well as the interior of the samples are carried out which reveal a clear difference. The grain size is observed to decrease with doping concentration. The “true switchable polarization” is deduced by positive up negative down (PUND) tests and found to decrease with doping. Fatigue behavior is found to be positively enhanced upon co-doping of 2% Nb and Fe. Leakage current tests are carried out and it is found that the samples become more ‘leaky’ upon co-doping of Nb and Fe. The energy storage density is also investigated for these Nb–Fe co-doped PLZT ceramics. The highest recoverable energy storage density is observed for 2% Nb–Fe co-doped PLZT sample and it is around 134 mJ/cm3 with an efficiency of 0.28.

20 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of Nb and Fe co-doping on PLZT lattice was investigated using X-ray diffraction and Raman spectroscopy.
Abstract: Nb and Fe co-doped PLZT (Pb0.97La0.02(Zr0.52Ti0.48)1−2x (Nb0.5Fe0.5)2x O3 for x = 0.00, 0.02, 0.04, 0.06 and 0.08) samples have been prepared using sol–gel method. X-ray diffraction (XRD) and Raman spectroscopy studies confirmed that the samples are single phase even for the highest tested doping of 8 mol% of Nb and Fe. Incorporation of Nb and Fe atoms into PLZT lattice has been confirmed by XRD study where a systematic peak shift has been observed with increasing dopant concentration. The lattice parameters are found to decrease gradually with increase in Nb and Fe contents. From Raman spectroscopic investigation, redshift of several modes has been observed. Rietveld refinement has been performed to correlate XRD results with the fitting of Raman spectra. A total of 14 distinguished modes have been identified by de-convolution of Raman spectra, and they are in good agreement with the theoretically calculated modes for PbTiO3 and also with those reported on PZT and PLZT previously. The Burstein–Moss shift of absorption edge has been observed by diffuse reflectance spectroscopy experiment, and the analysis shows change in band gap from 3.21 eV (for x = 0.00) to 2.59 eV (for x = 0.08). The underlying mechanisms and the observed electronic behavior have been confirmed and analyzed by photoluminescence study which revealed several transitions and supported the effect of Nb and Fe co-doping as observed from XRD and Raman spectroscopy.

20 citations


"Temperature Dependence of Energy St..." refers background or methods in this paper

  • ...Upon doping of certain elements in certain host lattices, the formation of impurity donor and acceptor bands are created inside the forbidden region [29]....

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  • ...To obtain a clearer picture of the bandgap the Kubelka-Munk method [29] is applied....

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