Effect Of Barium Substitution Research Articles

The effect of Barium substitution on the structural and dielectric properties of Pb1-XBaX(Zr0.52Ti0.43(Al0.5Sb0.5)0.05)O3 ceramics at the morphotropic phase boundary

In this study PZT type ceramics with a general formula Pb1- xBax(Zr0.52Ti0.43(Al0.5Sb0.5)0.05)O3 where (x = 0.00, 0.04, and 0.08) were elaborated by the solid-state reaction and studied for their structural and dielectric properties in the region of the morphotropic phase boundary (MPB). Different techniques were used to characterize the obtained samples such as X-ray diffraction (XRD) which shows that the results confirm the high purity of prepared samples without any secondary phase and also indicate the coexistence of both the tetragonal and rhombohedral phases. All the absorption bands corresponding to the perovskite structure are exhibited by The Fourier Transform Infrared spectroscopy (FTIR). The scanning electronic microscopy (SEM) shows that the mean grain size was found between 2,84 and 2,14 µm, the Curie temperature (TC) decreased with increasing Ba2+ content. Furthermore, the effect of the temperature, frequency, and composition on the dielectric properties demonstrated a maximum value of the dielectric constant ε max = 38800 at 1 kHz when X= 0.08.

Identification of barium-site substitution of BiFeO3–Bi0.5K0.5TiO3 multiferroic ceramics: X-ray absorption near edge spectroscopy

In this work, the effects of barium substitution on the local structure, dielectric and magnetic properties of the polycrystalline ceramics 0.6BiFeO3–0.4(Bi0.5K0.5)TiO3 (0.6BFO–0.4BKT) system was investigated. A solid-state reaction technique was used to synthesize the materials with barium (Ba) doping of 1, 3, 5, 7, and 10 mol%. XRD analysis reveals the coexistence between tetragonal and rhombohedral phases of single-phase perovskite in pure 0.6BFO–0.4BKT and the rhombohedral reach phase was found with increasing Ba content. XANES simulations indicate that the majority of Ba atoms occupy A-site in BKT lattice of Ba-doped 0.6BFO-0.4BKT, the oxidation state of Fe, Ti, and Ba ions are +3, +4 and+2, respectively. At 5 mol% of Ba doping content, the dielectric measurement shows the morphotropic phase boundary (MPB) and the maximum value of ferromagnetic characteristic were observed, indicating an optimum composition, properties and production conditions.

Effects of barium substitution on the optical and electrical properties of PLZT transparent electro-optical ceramics

Abstract Transparent electro-optic (EO) ceramics Pb0.91-xLa0.09Bax(Zr0.65Ti0.35)0.9775O3 (PLBZT x/9/65/35) with the amount of x = 0, 0.01, 0.02, 0.04 barium substitution for Pb at A-site were fabricated by hot pressing sintering process. The effects of barium substitution on the micro structure, ferroelectric, dielectric, optical and electro-optic birefringence properties were systematically studied. XRD result shows a typical ABO3 perovskite structure and no second phase observed within the detection limit, which clarifies the entry of Ba2+ ions into PLZT that caused the expansion of the crystal lattice. Due to the mixing ion effect of Pb2+, Ba2+ and La3+ at A-site, both coercive field (Ec) and remnant polarization (Pr) show reducing tendency with increasing doping. And the temperature of the dielectric maximum (Tm) was decreased almost linearly with increasing barium modifying amount. Especially, the reduction of the ferroelectric hysteresis was observed, which may reveal the Ba doping a new method to solve the problems faced now in device designing. In summary, the easily tuned Tm and slim hysteresis loop may prove PLBZT a promising candidate for optical modulator, light switch, energy storage and other relevant applications.

Effects of barium substitution on the dielectric properties of Sr(Fe0.5Nb0.5)O3 ceramics

The Ba-substituted Sr1−x Ba x (Fe0.5Nb0.5)O3 (SBFN, x = 0, 0.2, 0.5, 0.8) ceramics were prepared by a conventional solid-state sintering, and their microstructure and dielectric properties were investigated. The single-phase SBFN were obtained up to x = 0.8 Ba substitution and the lattice parameter increased with Ba substitution concentration. The dielectric constant increased with Ba substitution, and the highest value of ~180,000 was observed in the x = 0.8 Ba-substituted specimen at 1 kHz. Besides, the dielectric constant increased rapidly a giant value more than 106 over a broad temperature range for x = 0.8 Ba-substituted specimen. The obtained electric and dielectric properties in Ba-substituted SBFN were discussed in terms of the internal barrier layer capacitor model and electrode response.

Reply to the Comment on “The Effect of Barium Substitution on the Ferroelectric Properties of Sr2Nb2O7 Ceramics” [J. Am. Ceram. Soc., 96 [4] 1163–1170 (2013)

Reply to the Comment on “The Effect of Barium Substitution on the Ferroelectric Properties of Sr₂Nb₂O₇ Ceramics” [J. Am. Ceram. Soc., 96 [4] 1163–1170 (2013)

Comment on “The Effect of Barium Substitution on the Ferroelectric Properties of Sr2Nb2O7 Ceramics,” J. Am. Ceram. Soc., 96 [4] 1163–70 (2013)

Journal of the American Ceramic SocietyVolume 97, Issue 1 p. 326-327 Comment Comment on “The Effect of Barium Substitution on the Ferroelectric Properties of Sr2Nb2O7 Ceramics,” J. Am. Ceram. Soc., 96 [4] 1163–70 (2013) V. V. Atuchin, Corresponding Author V. V. Atuchin Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk, 630090 RussiaAuthor to whom correspondence should be addressed. e-mail: [email protected]Search for more papers by this author V. V. Atuchin, Corresponding Author V. V. Atuchin Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk, 630090 RussiaAuthor to whom correspondence should be addressed. e-mail: [email protected]Search for more papers by this author First published: 28 November 2013 https://doi.org/10.1111/jace.12651Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume97, Issue1January 2014Pages 326-327 RelatedInformation

Effect of Barium Substitution on Ferroelectric and Magnetic Properties of Bismuth Ferrite

We successfully synthesized Bi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Ba <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> FeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> = 0.0, 0.20, 0.25) replacing Bi by Ba using a chemical synthesis route. The phase and crystal structure of the samples were studied by X-ray diffraction (XRD). Peaks in the XRD shifted toward lower θ value with the increase in Ba concentration due to the increase in the unit cell size. Detail thermal behavior was performed by differential scanning calorimetry and differential thermal analysis (DTA) to investigate the change in magnetic and ferroelectric transition temperature, respectively, due to Ba substitution. Magnetic, dielectric, and magnetoelectric properties of the samples were also studied in detail. Antiferromagnetic bismuth ferrite was converted to ferromagnetic materials at room temperature on incorporating Ba in the crystal structure. Polarization versus electric field (P-E loop) and dielectric constant were also found to change significantly in the presence of a magnetic field in the aforementioned samples. Appreciable magnetodielectric effect [ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> (H)-ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> (0)]/ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> (0) also indicated effective magnetoelectric coupling within the materials.

Effects of Barium Substitution on the Structure and Properties of PSZT Piezoelectric Ceramics

Piezoelectric ceramics with appropriate curie temperatures and high dielectric and piezoelectric performances are attractive for formations of ceramic/polymer piezoelectric composites. The PSZT ceramics with compositions of 0.98Pb1.0-xBaxTi0.48Zr0.52O3-0.02PbSbO3 (x=0.14~0.24) have been prepared by a conventional solid reaction process. The ceramic structures are analyzed by X-ray diffraction and the barium substitution leads to structural changes of the tetragonal and rhombohedral phases which constitute the perovskite PSZT ceramics, and lattice distortions. The curie temperature almost linearly decreases from 226 °C to 141 °C corresponding the barium content increases from 0.14 to 0.24 in the ceramics. The dielectric and piezoelectric properties are largely influenced by the barium substitution and when the barium content at vicinity of 0.22, the piezoelectric strain constant d33 exhibits a dramatic change. It is found that as the barium content around 0.22, the PSZT ceramic specimen is characterized with a low curie temperature Tc=156 °C, and satisfied dielectric and piezoelectric properties with the relative dielectric constant εr=5873, dielectric loss factor tanδ=0.0387, piezoelectric strain constant d33=578 pC/N.

Development of superconducting phases in BSCCO and Ba-BSCCO by sol spray process

The effects of barium substitution for Bi or Sr sites on the growth of superconducting phases have been studied. The sol spray process has been used to synthesis the Bi-Sr-Ca-Cu-O (BSCCO) and Ba-BSCCO homogeneous ceramic powders. Thermogravimetric (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques were employed to characterize the synthesized materials. The electrical resistance was measured by classical d.c. fourprobe technique. It has been observed that sol spray process has affected the physico-chemical properties of the materials and also avoid the use of chelating agent as in the case of sol gel process. In addition to the Bi2Sr2CaCu2O8 (2212) phase Ba doped specimens also contained Bi2Sr2Ca2Cu3O10 (2223), BaBiO3, BaCuO2 and CuO phases.

Effect of Barium Substitution on Phase Transitions of Lead Barium Zirconate Ceramics Prepared by Solid State Reaction Method

The effect of Ba 2 + substitution on the phase transitions of (Pb 1 − x Ba x )ZrO 3 (PBZ) ceramics (0.0 ≤ x ≤ 0.30) has been investigated as a function of x. Phase formation and phase transition of PBZ 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 and rhombohedral for 0.20 ≤ x ≤ 0.30, whereas orthorhombic and rhombohedral phases coexist at x = 0.15. The proportion of ferroelectric and paraelectric phase in the samples gradually decreased with increasing Ba 2 + content.

Effects of Barium Substitution on Perovskite Formation, Dielectric Properties, and Diffuseness Characteristics of Lead Zinc Niobate Ceramics

Perovskite‐phase developments in partially/fully substituted (Ba,Pb)(Zn1/3Nb2/3)O3, synthesized via B‐site precursor routes, were investigated. The pyrochlore structure, present at no barium content, was immediately replaced by perovskite with a small amount (≥8 at.%) of barium substitution. Variations in the lattice parameters of the pyrochlore and perovskite structures were studied. The weak‐field radio‐frequency dielectric constants and losses of the system ceramics were examined. A highest maximum dielectric constant of 9000 (76°C, 1 MHz) was observed at 8 at.% barium substitution. The dielectric‐constant spectra were analyzed further in terms of diffuseness characteristics (e.g., diffuseness exponent and degree of diffuseness). The dielectric hysteresis loops of the ceramics were measured. The microstructures of the sintered ceramics also were observed.

Effect of barium substitution at the yttrium site in YBa2Cu3O7?y prepared from nitrate precursors

Effect of barium substitution at the yttrium site in YBa2Cu3O7?y prepared from nitrate precursors

Structural, magnetic, and electrical properties of La 2−xBa xNiO 4

Polycrystalline samples of the composition La 2−xBa xNiO 4 (0 ≤ x ≤ 1) were prepared by standard solid state chemistry techniques. The samples were characterized by x-ray diffraction, magnetic susceptibility in the temperature range 6 to 300 K, and room temperature electrical resistivity. The effect of barium substitution on the structural, magnetic, and electrical properties is reported.

The calcium current in a myenteric neurone of the guinea-pig ileum.

The active and passive electrical properties of the after-hyperpolarizing (AH) cell of the guinea-pig myenteric plexus were analysed using a single-electrode voltage or current clamp. Action potentials were compared under normal conditions, in the presence of tetrodotoxin (TTX) and in the presence of both TTX and tetraethylammonium chloride (TEA). Calcium action potentials were studied by examining their calcium dependence, the actions of manganese and the effect of substituting barium for calcium. The maximum rate of rise of the action potential did not increase in calcium concentrations above 10 mM. The half-saturation concentration was 2 mM-calcium. AH cells exhibited five predominant currents consisting of an inward sodium current, an inward calcium current and three outward currents. There was a transient outward current which was inactivated at holding potentials more positive than -65 mV and was suppressed by 4-aminopyridine and barium but not by external TEA. A second outward current observed in the presence of 10 mM-external TEA had properties consistent with that of the delayed rectifier (Hodgkin & Huxley, 1952). A third outward current was the calcium-dependent slow after-hyperpolarizing current (Hirst, Johnson & van Helden, 1985). The voltage dependence, the action of calcium antagonists, the effect of barium substitution and the temporal characteristics of calcium currents were studied. The peak calcium current density was in excess of 100 microA/cm2 in 2.5 mM-calcium solution at 35 degrees C for depolarizations to -10 mV. Calcium currents showed at least two phases of inactivation. Both calcium and barium currents showed early inactivation with decay occurring over the first 10-40 ms. The calcium-activated current precluded direct measurement of slow inactivation of the calcium current. Barium currents studied over the first 100-150 ms had a very slow inactivating component.