Dielectric and Ferroelectric Properties of BaTi1-xSnxO3 Multilayered Ceramics

2007 ◽  
Vol 555 ◽  
pp. 249-254 ◽  
Author(s):  
S. Marković ◽  
M. Mitrić ◽  
Č. Jovalekić ◽  
M. Miljković
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Ferroelectric Properties ◽  
X Ray ◽  
High Dielectric ◽  
Scanning Electron

Multilayered BaTi1-xSnxO3 (BTS) ceramics with different Ti/Sn ratios were produced by pressing and sintering at 1420 oC for 2 hours. X-ray diffractometry, scanning electron microscopy and energy dispersive spectroscopy were used for structural, microstructural and elemental analysis, respectively. The dielectric and ferroelectric behavior of sintered samples was studied, too. It is found that in ingredient materials, with increasing Sn content, the tetragonality decreases; Curie temperature moves towards room temperature, while the maximum of the dielectric constant increases, and also, they becomes less hysteretic. It is noticed that multilayered BTS ceramics with different Ti/Sn contents have a broad transition temperature and show a relatively high dielectric constant in a wide temperature range. It is shown that dielectric properties of these materials may be modified by a combination of different BTS powders as well as layers number.

Identification of Nd163 phase in melt-textured NdBa2Cu3O7−δ bulk samples

2003 ◽  
Vol 18 (9) ◽  
pp. 2050-2054 ◽  
Author(s):  
Marcello Gombos ◽  
Vicente Gomis ◽  
Anna Esther Carrillo ◽  
Antonio Vecchione ◽  
Sandro Pace ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Room Temperature ◽  
Polarized Light ◽  
Energy Dispersive ◽  
X Ray ◽  
Spontaneous Formation ◽  
The Stability ◽  
Scanning Electron

In this work, we report on the observation of Nd1Ba6Cu3O10,5 (Nd163) phase of the NdBaCuO system in melt-textured Nd123 bulk samples grown from a mixture of Nd123 and Nd210 phase powders. The observation was performed with polarized light optical microscopy and scanning electron microscopy–energy dispersive x-ray analyses. Images of the identified phase crystals show an aspect quite different from Nd422 crystals. Unexpectedly, Nd163 was individuated, even in “pure” Nd123 samples. Moreover, after long exposure to air, Nd163 disappeared completely in samples synthesized from powders containing Nd210. Thermogravimetry analyses of powders show that the stability of this phase in air is limited to temperatures higher than 900 °C, so Nd163 is unstable and highly reactive at room temperature. Moreover, an explanation of the observation of Nd163 in Nd210 free samples, based on the spontaneous formation of Nd163 phase in a Nd123 melt, is proposed.

N-type Ba0.2Co4Sb11.5Te0.5: Optimization of thermoelectric properties by different pressures

2019 ◽  
Vol 33 (03) ◽  
pp. 1950027 ◽  
Author(s):  
Jiaxiang Chen ◽  
Xiaopeng Jia ◽  
Yuewen Zhang ◽  
Haiqiang Liu ◽  
Baomin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Seebeck Coefficient ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Absolute Value ◽  
X Ray ◽  
Coefficient Increase ◽  
Maximum Power Factor ◽  
Scanning Electron

The polycrystalline skutterudite [Formula: see text] were successfully synthesized from 1.5 GPa to 3.5 GPa by the high pressure and high temperature (HPHT) method. Negative Seebeck coefficient confirmed the n-type conductivity of all samples. The phase compositions of samples were investigated by X-ray diffraction (XRD) and the microstructures were observed by scanning electron microscopy (SEM). It was found that the grains appeared smaller and the grain boundaries became more abundant when pressures were higher. We measured the electrical properties from room temperature to 723 K. Both the electrical resistivity and absolute value of Seebeck coefficient increase with the increasing synthetic pressure. At 723 K, the maximum power factor of [Formula: see text] was obtained for the sample synthesized under 3 GPa. The maximum ZT value of 0.61 was reached by [Formula: see text] synthesized under 3 GPa and measured at 723 K.

Phase Development and Dielectric Properties of 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3 Ceramic

2011 ◽  
Vol 700 ◽  
pp. 58-62
Author(s):  
Rachanusorn Roongtao ◽  
Supagorn Rugmai ◽  
Wanwilai C. Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Factor ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Phase Development ◽  
Scanning Electron

The 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3ceramics has been synthesized through a conventional mixed-oxide by using BT nanopowder and BMN micropowder. The phase purity of the powders and the ceramics was examined using X-ray diffraction (XRD). The 0.98BT-0.02BMN powders were sintered to 92% of the theoretical density at a temperature of 1300 °C for 2 h. The microstructure of the sintered surface was investigated using scanning electron microscopy (SEM). The dielectric constant (εr) and loss factor (tanδ) of the sintered pellets at Curie temperture were 3000 and 0.015, respectively.

scholarly journals Hydrothermal synthesis and characteristics of lanthanumdoped pb(Zr₀.₆₅Ti ₀.₃₅)O₃ ceramics

2021 ◽  
Vol 8 (3) ◽  
pp. 14-19
Author(s):  
Thuy Nguyen Thanh ◽  
Tung Nguyen Van ◽  
Hung Nguyen Trong ◽  
Minh Cao Duy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Reaction Temperature ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Influence Of Ph ◽  
Scanning Electron

Lanthanum-doped lead zirconate titanate (PLZT) powders were synthesized using thehydrothermal method. The influence of pH, reaction temperature and time, lanthanum concentration on the formation and characteristics of PLZT were investigated. Obtained powders were investigated using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) techniques and a dielectric analyzer. The results showed that           Pb1-xLax(Zr0.65Ti0.35)O3 with x= 0.0 – 0.1 were well formed under conditions: pH≥13, reaction time of 12hrs, reaction temperature of 180oC. Dielectric constant of PLZT is higher than PZT. The grain size of the PLZT is found to be 1–3.5 µm.

scholarly journals Preparation and Phase Relations in the CuSbSe2 – CuInSe2 System

2016 ◽  
Vol 1735 ◽  
Author(s):  
Barys V. Korzun ◽  
Valery R. Sobol ◽  
Marin Rusu ◽  
Ruben M. Savizky ◽  
Alena A. Fadzeyeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Mole Fraction ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Phase Relations ◽  
X Ray ◽  
Ternary Compounds ◽  
Scanning Electron

ABSTRACTThe CuInSe2 and CuSbSe2 ternary compounds and alloys of the (CuSbSe2)1-x·(CuInSe2)x system with the mole fraction of CuInSe2 (x) equal to 0.05, 0.15, 0.25, 0.375, 0.50, 0.625, 0.75, 0.85, and 0.95 were prepared and the phase relations in this system were investigated by X-ray powder diffraction, optical microscopy, and scanning electron microscopy. It was shown that the alloys of the CuSbSe2-CuInSe2 system are biphasic at room temperature in the whole range of compositions, and the limits of solubility for CuSbSe2 in CuInSe2 and for CuInSe2 in CuSbSe2 do not exceed 0.001 mole fraction.

Synthesis of Silicon Carbide Nanoparticles from Carbon Nanotubes

2012 ◽  
Vol 602-604 ◽  
pp. 183-186 ◽  
Author(s):  
Jing Liu ◽  
Rong Wu ◽  
Jin Li ◽  
Yan Fei Sun ◽  
Ji Kang Jian
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Room Temperature ◽  
Sic Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Cubic Silicon Carbide ◽  
Scanning Electron

In this paper, we report the synthesis of cubic silicon carbide (3C-SiC) nanoparticles by direction reaction of silicon powders and carbon nanotubes. The as-prepared SiC nanoparticles were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and Raman scattering at room temperature. The possible growth mechanism is proposed.

Precursors Influence on CaCu3Ti4O12 Synthesis

2012 ◽  
Vol 727-728 ◽  
pp. 1313-1316 ◽  
Author(s):  
Maria Virginia Gelfuso ◽  
Gabriel Moreira Lima ◽  
Daniel Thomazini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Room Temperature ◽  
Microstructural Analysis ◽  
Copper Nitrate ◽  
N Powder ◽  
Scanning Electron

In this work CCTO have been synthesized in two different chemical precursors: calcium hydroxide and copper sulfate were used to compose CCTO-S powder while calcium carbonate and copper nitrate were used to form CCTO-N powder. Calcinations conditions were dramatically different in terms of shelf time and temperature. The CCTO phase was fully obtained for 3 hours of calcination in CCTO-N against the 24 hours to form the same phase in CCTO-S powder. Ceramic bodies densities values for CCTO-S samples were 95% of theoretical density (5.05 g/cm3) and 98% for CCTO-N. The dielectric constant, at room temperature, was obtained for ceramics processed by two routes. Microstructural analysis was conducted by Scanning Electron Microscopy (SEM) and it was performed to explain the dielectric constant differences between CCTO-S and CCTO-N ceramics.

Preparation of Hollow Nickel Ferrite Microspheres and their Magnetic Properties

2014 ◽  
Vol 1035 ◽  
pp. 488-491
Author(s):  
Jing Jing Li ◽  
Yun Zhao ◽  
Han Sheng Li ◽  
Qin Wu ◽  
Qing Ze Jiao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nickel Ferrite ◽  
Room Temperature ◽  
Solvothermal Method ◽  
Magnetization Measurement ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Hollow nickel ferrite microspheres with a diameter of about 1.5 to 2.5 μm were synthesized using an emulsion-based solvothermal method in combination with calcination at 550°C. The structures and morphologies of the nickel ferrite microspheres were characterized using an X-ray diffractometer, a transmission electron microscopy and a field emission scanning electron microscopy. Magnetization measurement was carried out using a vibrating sample magnetometer at room temperature. The saturation magnetization and coercivity of nickel ferrite microspheres could reach 19.41 emu/g and 202.28 Oe, respectively. Hollow nickel ferrite microspheres might be used as catalysts, magnetic materials and microwave absorbers.

Synthesis of Nanophase Noble Metal Systems Utilizing Porous Silicon

1996 ◽  
Vol 457 ◽  
Author(s):  
I. Coulthard ◽  
T. K. Sham
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Porous Silicon ◽  
Noble Metal ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Visible Range ◽  
X Ray ◽  
Metallic Salt ◽  
Scanning Electron

ABSTRACTApart from its well known ability to luminesce very intensely at room temperature in the visible range, porous silicon is also an effective reducing agent. We report the formation of several noble metal (Pd, Ag, Au, Pt) nanostructures by reductive dispersion of metal ions from aqueous solutions onto the surface of porous silicon. The nanophase systems produced by reductive deposition vary with the element deposited and the metallic salt utilized in the process. The resulting nanophase systems were studied using a variety of techniques including: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopie methods using synchrotron radiation.

Ferroelectric properties in all solution prepared Bi6Fe2Ti3O18/Ba0.92La0.08SnO3 thin films

2016 ◽  
Vol 30 (35) ◽  
pp. 1650394
Author(s):  
Li Zhang ◽  
Yibao Li ◽  
Zhen Tang ◽  
Yan Deng ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Coercive Field ◽  
Ferroelectric Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transparent Conducting ◽  
Scanning Electron

In this paper, all solution processing is used to prepare both the transparent conducting Ba[Formula: see text]La[Formula: see text]SnO3 (BLSO) thin films as bottom electrodes and ferroelectric Bi6Fe2Ti3O[Formula: see text] (BFTO) thin films. The derived BFTO thin films are characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The derived thin film is polycrystalline with dense microstructures. The remnant polarization [Formula: see text] at the measurement frequency of 2 kHz can reach [Formula: see text] under the 500 kV/cm electric field and the coercive field [Formula: see text] is 410 kV/cm. The results will provide a feasible route to prepare BFTO thin films on transparent conducting bottom electrodes to realize multifunctionality.

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