Effect of sintering temperature on structural, electrical, and ferroelectric properties of lanthanum and sodium co-substituted barium titanate ceramics

Alkathy, Mahmoud S.; Hezam, Abdo; Manoja, K.S.D.; Wang, Jingwei; Cheng, Chun; Byrappa, K.; Raju, K. C. James

doi:10.1016/j.jallcom.2018.05.138

Cited by 40 publications

(23 citation statements)

References 75 publications

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“…Barium titanate tetragonal phase (PDF 5-626) is evidenced by the presence of a doublet at 2θ = 45° [ 52 , 53 ], whereas the cubic phase (PDF 31-174) is recognized by a single peak at 2θ = 45°and the coexistence of the two phases by a main peak combined with a shoulder. As shown in Figure 7 , XRD pattern of commercial powders clearly presents a doublet, while annealed powders from sol−gel both at ambient pressure and hydrothermal condition present an intermediate situation, with the main peak and a shoulder ( Figure 7 , inset), evidence of the coexistence of both tetragonal and cubic phase.…”

Section: Resultsmentioning

confidence: 99%

Effect of Hydrothermal Treatment and Doping on the Microstructural Features of Sol-Gel Derived BaTiO3 Nanoparticles

et al. 2021

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Barium Titanate (BaTiO3) is one of the most promising lead-free ferroelectric materials for the development of piezoelectric nanocomposites for nanogenerators and sensors. The miniaturization of electronic devices is pushing researchers to produce nanometric-sized particles to be embedded into flexible polymeric matrices. Here, we present the sol-gel preparation of crystalline BaTiO3 nanoparticles (NPs) obtained by reacting barium acetate (Ba(CH3COO)2) and titanium (IV) isopropoxide (Ti(OiPr)4). The reaction was performed both at ambient conditions and by a hydrothermal process carried on at 200 °C for times ranging from 2 to 8 h. Doped BaTiO3 nanoparticles were also produced by addition of Na, Ca, and Bi cations. The powders were annealed at 900 °C in order to improve NPs crystallinity and promote the cubic-to-tetragonal (c⟶t) phase transformation. The microstructural features of nanoparticles were investigated in dependence of both the hydrothermal reaction time and the presence of dopants. It is found that short hydrothermal treatment (2 h) can produce BaTiO3 spherical and more homogeneous nanoparticles with respect to longer hydrothermal treatments (4 h, 6 h, 8 h). These particles (2 h) are characterized by decreased dimension (approx. 120 nm), narrower size distribution and higher tetragonality (1.007) in comparison with particles prepared at ambient pressure (1.003). In addition, the short hydrothermal treatment (2 h) produces particles with tetragonality comparable to the one obtained after the longest process (8 h). Finally, dopants were found to affect to different extents both the c⟶t phase transformation and the crystallite sizes.

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Section: Resultsmentioning

confidence: 99%

Effect of Hydrothermal Treatment and Doping on the Microstructural Features of Sol-Gel Derived BaTiO3 Nanoparticles

et al. 2021

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“…For the BaTiO3 particles, there is an intense band near 529.2 eV assigned to oxygen atoms in the Ba-O-Ti structure. 49,50 In the case of the aged BaTiO3/TiO2 particles, this peak appears at 530.1 eV and it is attributed to the oxygen atoms in Ti-O-Ti structure. 49,50 The peak at 530.5 eV (BaTiO3 particles) or at 531.3 eV (aged BaTiO3/TiO2 particles) corresponds to the hydroxyl group on the surface of nanoparticles.…”

Section: Resultsmentioning

confidence: 99%

“…49,50 In the case of the aged BaTiO3/TiO2 particles, this peak appears at 530.1 eV and it is attributed to the oxygen atoms in Ti-O-Ti structure. 49,50 The peak at 530.5 eV (BaTiO3 particles) or at 531.3 eV (aged BaTiO3/TiO2 particles) corresponds to the hydroxyl group on the surface of nanoparticles. 47 The O1s emission line at 531.7 eV (BaTiO3 particles) or at 531.9 eV (aged BaTiO3/TiO2 particles) is assigned to the absorbed oxygen as O-C of CO2.…”

Section: Resultsmentioning

confidence: 99%

Revealing the Role of the Intermediates during the Synthesis of BaTi₅O₁₁

et al. 2019

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BaTi5O11 has been extensively studied because of their microwave dielectrics properties. Traditionally, it is difficult to achieve this material as single-phase. Here, we report an effective method to obtain BaTi5O11 powder with nanometerscale crystals, by solid-state reaction at moderate temperatures and using as precursors nanostructured particles consisting of BaTiO3 and TiO2. The main advantage is the intimate contact between the BaTiO3 and TiO2 that ensure, when the solid-state reaction takes place, the formation of complex solid compounds from three or more constituents. The formation mechanism of BaTi5O11 has been studied as a function of both the thermal treatment and the time reaction. The reaction was monitored by Raman spectroscopy combined with Confocal microscopy, the aim of this characterization technique is to provide the description of the general strategy and design principles to obtain BaTi5O11 powder. Consequently, this work is a challenging task for the compositional and structural study of complex inorganic nanoparticles.

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“…It has been carried out, such as crystal defect chemistry of REcations in BT. [7][8][9] Significantly, rare-earths "RE" dopants are one of the most notable substitutions, for instance; Lanthanide doped BaTiO3 is of considerable importance to the modern electronics industry. [10][11] In addition, La 3+ ions can typically decrease the dielectric loss of barium titanate ceramics; moreover, niobium can properly curb the growth of the grains of the barium titanate ceramic and lead to a considerable drop in the Curie temperature.…”

Section: Introductionmentioning

confidence: 99%

DC-Bias Dependent Impedance and UV-Vis Diffuse Reflectance Spectroscopy of The Un-Doped and Nb-Doped Ba0.97La0.02TiO3 Ceramics

Jebli

Hamadoui

rayssi

et al. 2021

Preprint

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This report typically discusses the Voltage-Stability (V-S) of the electrical properties of a new perovskite oxide, Ba0.97La0.02Ti1-xNb4x/5O3 (noted BLT, BLT0.9Nb0.08) ceramics which have been meticulously studied. The ceramics typically exhibited a low rise in the real and imaginary parts of the complex impedance on the application of small field levels (up to 5 V). These accurate data, at a low voltage threshold, properly designate a hole-generation process which becomes active. These values considered using AC impedance spectroscopy, nonetheless, were relatively decreased with increasing Nb concentration, as well as increased by this application of a DC bias. For each sample, the complex impedance plot displayed a single impedance semicircle, identified over the high and low frequencies. The equivalent circuit configuration was typically fitted using the Electrochemical Impedance Spectroscopy (EIS) spectra analyzer. Importantly, the electrical properties of our both compounds deduced from the complex electric modulus show a conduction process due to the short-range mobility of charge carriers. An excellent addition of Niobium to some considerable extent can inhibit the grain growth. Conspicuously, the substitution of Nb5+ ions for Ti4+ on B sites leads to the noticeable increase of a band gap. These findings supplied critical insights into the electric mechanisms in BT-based ceramics.

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Effect of sintering temperature on structural, electrical, and ferroelectric properties of lanthanum and sodium co-substituted barium titanate ceramics

Cited by 40 publications

References 75 publications

Effect of Hydrothermal Treatment and Doping on the Microstructural Features of Sol-Gel Derived BaTiO3 Nanoparticles

Effect of Hydrothermal Treatment and Doping on the Microstructural Features of Sol-Gel Derived BaTiO3 Nanoparticles

Revealing the Role of the Intermediates during the Synthesis of BaTi₅O₁₁

DC-Bias Dependent Impedance and UV-Vis Diffuse Reflectance Spectroscopy of The Un-Doped and Nb-Doped Ba0.97La0.02TiO3 Ceramics

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Effect of sintering temperature on structural, electrical, and ferroelectric properties of lanthanum and sodium co-substituted barium titanate ceramics

Cited by 40 publications

References 75 publications

Effect of Hydrothermal Treatment and Doping on the Microstructural Features of Sol-Gel Derived BaTiO3 Nanoparticles

Effect of Hydrothermal Treatment and Doping on the Microstructural Features of Sol-Gel Derived BaTiO3 Nanoparticles

Revealing the Role of the Intermediates during the Synthesis of BaTi5O11

DC-Bias Dependent Impedance and UV-Vis Diffuse Reflectance Spectroscopy of The Un-Doped and Nb-Doped Ba0.97La0.02TiO3 Ceramics

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Revealing the Role of the Intermediates during the Synthesis of BaTi₅O₁₁