Application of Impedance Spectroscopy for Bi1−xNdxFeO3 Ceramics Characterization

2012 ◽  
Vol 730-732 ◽  
pp. 71-75
Author(s):  
Beata Wodecka-Dus ◽  
Jolanta Dzik ◽  
Henryk Bernard ◽  
Katarzyna Osinska ◽  
Agata Lisińska-Czekaj ◽  
...  
Keyword(s):  
Solid State ◽  
Impedance Spectroscopy ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Frequency Range ◽  
Reaction Method ◽  
Synthesis Conditions

In the present paper the synthesis conditions for fabrication of Bi1−xNdxFeO3ceramics are reported. The single phase polycrystalline samples of Bi1−xNdxFeO3 were prepared by standard solid state reaction method from the mixture of oxides viz.: Bi2O3, Fe2O3and Nd2O3. The samples were characterized by impedance spectroscopy in the frequency range 10Hz – 1MHz at room temperature.

Facile preparation of polyoxometalate nanoparticles via a solid-state chemical reaction for aerobic oxidative desulfurization catalysis

2021 ◽  
Author(s):  
Hang Yu ◽  
Wenwen Bu ◽  
Zijia Wang ◽  
Zhuoyue Zhao ◽  
Mehwish Jadoon ◽  
...  
Keyword(s):  
Solid State ◽  
Silver Nitrate ◽  
Chemical Reaction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Oxidative Desulfurization ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
State Chemical ◽  
Facile Preparation

Polyoxometalate nanoparticles were synthesized via a concise solid-state reaction method by directly grinding silver nitrate and the polyoxometalate (NH4)5H6PMo4V8O40 at room temperature without the assistance of a surfactant.

scholarly journals Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

2016 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Lcr Meter ◽  
Curie Temperature Tc

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

Luminescence Properties of Self-Activated M3(VO4)2 (M = Mg, Ca, Sr, and Ba) Phosphors Synthesized by Solid-State Reaction Method

2016 ◽  
Vol 16 (4) ◽  
pp. 3684-3689 ◽  
Author(s):  
Xin Min ◽  
Zhaohui Huang ◽  
Minghao Fang ◽  
Yan’gai Liu ◽  
Chao Tang ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Uv Light ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Reaction Method ◽  
X Ray ◽  
Yield Decrease

In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V–V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs).

scholarly journals Thermoelectric properties of LaFeO3 system with doped Ti, Co, Cu

2017 ◽  
Vol 126 (1B) ◽  
pp. 147
Author(s):  
Nguyen Thi Thuy
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Room Temperature ◽  
Unit Cell Volume ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Scanning Electron

<p><strong>Abstract: </strong>LaFeO<sub>3</sub> system with doped Ti, Co, Cu was manufactured by solid state reaction method, it was sintered at 1250<sup>0</sup>C and 1290<sup>0</sup>C in 10 hours with a heating rate of 3<sup>0</sup>C/min. Using X-ray diffraction and Scanning Electron Microscope (SEM) to examine the structure, it reveals that samples are single-phase and orthogonal-perovskite structure describing by the Pnma space group, the unit cell volume of the samples increases when Ti, Co, Cu are doped to replace ion Fe<sup>+3</sup>. The size of particle increase while raising the temperature of sintering. Measuring the resistance which depends on temperature between the room temperature and 1000K, it can be seen that when doping Co, Cu with the nominal component La(Fe<sub>0,2</sub>Co<sub>0,2</sub>Ti<sub>0,6</sub>)O<sub>3</sub> and La(Fe<sub>0,4</sub>Cu<sub>0,1</sub>Ti<sub>0,5</sub>)O<sub>3 </sub>, the conductivity of samples increases respectively. Especially, the conductivity of Cu doped sample is higher than two other samples, and reach the highest conductivity at about 900<sup>0</sup>C, Seebeck coefficient S of La(Fe<sub>0.6</sub>Ti<sub>0.4</sub>)O<sub>3</sub> can be change from positive to negative at the temperature of around 700<sup>0</sup>C.</p>

Effects of Various Fluxes on Synthesis of Deep Red Emitting CaAl12O19:Mn4+ Phosphors

2016 ◽  
Vol 852 ◽  
pp. 454-460 ◽  
Author(s):  
Qiu Hong Zhang ◽  
Hai Yong Ni ◽  
Ling Li Wang ◽  
Fang Ming Xiao
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Luminescent Intensity ◽  
Reaction Method ◽  
Structure Morphology ◽  
Forming Temperature

Deep red emitting CaAl12-xO19:xMn4+ phosphors were synthesized by solid state reaction method. Various fluxes (BaF2, H3BO3, Na2CO3 and NH4Cl) were added in preparation of the phosphors. The influences of the various fluxes on the crystal structure, morphology and luminescent properties of CaAl12O19:Mn4+ phosphors were studied. The results show that the obtained phosphors with fluxes possessed better luminescent intensity than that of the phosphors without fluxes. The maximum luminescent intensities were found with the following order: H3BO3 (2.0 wt%) > Na2CO3 (0.5 wt%) > NH4Cl (0.3 wt%) > BaF2 (0.1 wt%) > no flux. The H3BO3 flux can decrease the single phase forming temperature of CaAl12O19:Mn4+ phosphors by about 150°C.

Dielectric Properties of Zr-Doped CaCu3Ti4O12 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 129-131
Author(s):  
Yong He ◽  
Ke Pi Chen ◽  
Dong Yu Liu ◽  
Zong De Liu
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Impedance Spectroscopy ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Obvious Effect ◽  
Reaction Method ◽  
Microstructure Characteristic

CaCu3(Ti1-xZrx)O12 ceramics (x = 0.02, 0.04, 0.06, 0.08) were prepared by the conventional solid-state reaction method. Phase compositions, microstructure and dielectric properties were examined by XRD, SEM and impedance spectroscopy, respectively. The experimental results indicated that there is no obvious effect on microstructure characteristic by substituting Zr4+ for Ti4+. It was found that the values of the dielectric constant for all of the samples dropped into the order of 102, which is significantly lower than the order of 105 that of normally reported in the literature. It was suggested that the presence of impurity phases played an important role for the degeneracy of dielectric properties.

scholarly journals Synthesis of Vanadium (III) Doped Anatase TiO2 by Solid State Reaction Method

ALCHEMY ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
Nur Aini ◽  
Rachamawati Ningsih
Keyword(s):  
Solid State ◽  
Visible Light ◽  
Solid State Reaction ◽  
Single Phase ◽  
Diffuse Reflectance Spectroscopy ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Vanadium Doping

Anatase of Titanium dioxide (TiO<sub>2</sub>)  was doped with vanadium ions (V<sup>3+</sup>), at doping levels ranging from 0.3, 0.5 to 0.7 atomic percentage in order to increase its photocatalytic activity under visible light irradiation. Vanadium doped TiO<sub>2</sub> was synthesized by solid state reaction method. Its physicochemical properties characterized by powder X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectroscopy (DRS). Doping with V(III) resulted in a single phase structure of anatase TiO<sub>2</sub> with nanosize crystal ranging from 53.06 to 59.59 nm. Vanadium doping also resulted in a red-shift of the photophysical response of TiO<sub>2</sub> that was reflected in an extended absorption in the visible light between 400 and 700 nm.

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