scholarly journals Structural, Magnetic, Dielectric and Piezoelectric Properties of Multiferroic PbTi1−xFexO3−δ Ceramics

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 927
Author(s):  
Khiat Abd Elmadjid ◽  
Felicia Gheorghiu ◽  
Mokhtar Zerdali ◽  
Ina Turcan ◽  
Saad Hamzaoui
Keyword(s):  
Oxygen Vacancies ◽  
Oxygen Deficiency ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Solid State Reaction Method ◽  
Magnetic Characteristics ◽  
Sem Images ◽  
Intergranular Porosity ◽  
Complex Impedance Analysis ◽  
Magnetic Dielectric

PbTi1−xFexO3−δ (x = 0, 0.3, 0.5, and 0.7) ceramics were prepared using the classical solid-state reaction method. The investigated system presented properties that were derived from composition, microstructure, and oxygen deficiency. The phase investigations indicated that all of the samples were well crystallized, and the formation of a cubic structure with small traces of impurities was promoted, in addition to a tetragonal structure, as Fe3+ concentration increased. The scanning electron microscopy (SEM) images for PbTi1−xFexO3−δ ceramics revealed microstructures that were inhomogeneous with an intergranular porosity. The dielectric permittivity increased systematically with Fe3+ concentration, increasing up to x = 0.7. A complex impedance analysis revealed the presence of multiple semicircles in the spectra, demonstrating a local electrical inhomogeneity due the different microstructures and amounts of oxygen vacancies distributed within the sample. The increase of the substitution with Fe3+ ions onto Ti4+ sites led to the improvement of the magnetic properties due to the gradual increase in the interactions between Fe3+ ions, which were mediated by the presence of oxygen vacancies. The PbTi1−xFexO3−δ became a multifunctional system with reasonable dielectric, piezoelectric, and magnetic characteristics, making it suitable for application in magnetoelectric devices.

Grain boundary effects in NTC-PTC composite thermistor materials

1999 ◽  
Vol 14 (1) ◽  
pp. 120-123 ◽  
Author(s):  
D. J. Wang ◽  
J. Qiu ◽  
Y. C. Guo ◽  
Z. L. Gui ◽  
L. T. Li
Keyword(s):  
Energy Level ◽  
Grain Boundary ◽  
Boundary Effect ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Impedance Analysis ◽  
Composite Effect ◽  
Complex Impedance Analysis ◽  
Temperature Coefficient Of Resistivity ◽  
Grain Boundary Effect

Yttrium-doped (Sr0.45Pb0.55)TiO3 ceramics have been studied by complex impedance analysis. As a sort of NTC-PTC composite thermistor, it exhibited a significantly large negative temperature coefficient of resistivity below Tc in addition to the ordinary PTC characteristics above Tc. It is found that the NTC effect in NTC-PTC materials was not originated from the deep energy level of donor (bulk behavior), but from the electrical behavior of the grain boundary. Therefore, the NTC-PTC composite effect was assumed to be a grain boundary effect, and yttrium was a donor at shallow energy level. The NTC-PTC ceramics were grain boundary controlled materials.

Upshot of Concentration of Zirconium (IV) Oxynitrate Hexa Hydrate on Preparation and Analyses of Zirconium Oxide (ZrO2) Nanoparticles by Modified Co-Precipitation Method

2021 ◽  
Vol 21 (11) ◽  
pp. 5707-5713
Author(s):  
M. Ramachandran ◽  
R. Subadevi ◽  
P. Rajkumar ◽  
R. Muthupradeepa ◽  
R. Yuvakkumar ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Raw Material ◽  
Precipitation Method ◽  
Zro2 Nanoparticles ◽  
Fixed Amount ◽  
Complex Impedance Analysis ◽  
Dta Analysis ◽  
Co Precipitation

In the present work, pure nanocrystalline monoclinic Zirconia (ZrO2) has been successfully synthesized and optimized by the modified co-precipitation method. The concentration of raw material has been optimized with the fixed amount of precipitation agent (Potassium hydroxide KOH). The thermal history of the precursor has been examined through TG/DTA analysis. All the samples are subjected to study the structure, fingerprints of the molecular vibrations, and morphology analyses. The representative sample has been analyzed through Transmission Electron Microscope (TEM) and X-ray Photo Electron Spectroscopy (XPS) analyses. The as-prepared sample exhibits the better crystallinity and surface morphology with lesser particle size (190 nm) when the raw material concentration is 0.2 M. The as-prepared ZrO2 filler (0, 3, 6, 9, and 12 wt.%) is spread through the enhanced polymer electrolyte P(S-MMA) (27 Wt.%)-LiClO4 (8 wt.%)-EC + PC (1;1 of 65 wt.%) complex system via solution casting method. The as-synthesized electrolyte films are examined via complex impedance analysis. P(S-MMA) (27 wt.%)-LiCIO4 (8 wt.%)-EC + PC (1 ;1 of 65 wt.%)-6 wt.% of ZrO2 shows the high ionic conductivity 2.35 × 10–3 Scm–1. Temperature-dependent ionic conductivity studies obey the non-linear behavior. The enhanced ZrO2 has been expected to enhance the other electrochemical properties of the lithium secondary battery.

scholarly journals The effects of calcination and doping on structural and dielectric properties of CaCu3-xCoxTi4O12 ceramic

2019 ◽  
Vol 8 (3) ◽  
pp. 234
Author(s):  
Nasr Hadi ◽  
Tajdine Lamcharfi ◽  
Farid Abdi ◽  
Nor-Said Echtoui ◽  
Ahmed Harrach ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Xrd Analysis ◽  
Secondary Phases ◽  
Solid State Method ◽  
Complex Impedance Analysis ◽  
Oxide Powders ◽  
Increasing Temperature

<p class="Abstract"><span lang="EN-US">The influences of calcination temperature and doping with cobalt in A–site on structural and dielectric properties of CaCu<sub>3-x</sub>Co<sub>x</sub>Ti<sub>4</sub>O<sub>12</sub> (CCCxTO, x = 0.00, 0.02 and 0.10) ceramics sintered at 1050 <sup>0</sup>C for 8h were investigated. The ceramic samples are prepared by the conventional solid-state method using high purity oxide powders, and they are calcined at 850 °C, 950 °C and 1050 <sup>0</sup>C for 4h. The X-ray diffraction (XRD) analysis of pure and doped CCTO samples calcined at 950 °C and 1050 <sup>0</sup>C showed no traces of any other secondary phases, while impurity phases alongside CCTO phase in the x=0.00 sample calcined at 850 <sup>0</sup>C was observed. Scanning electron microscopy (SEM) investigation showed an increase in grain size with increasing of Co content and calcining temperature. Dielectric measurements indicated that the dielectric constant of the pure CCTO calcined at 1050 <sup>0</sup>C/4h has a low value in the frequency range of 1kHz up to 1MHz, whereas the substitution of Co up to x = 0.10 into CCTO caused a huge increase in the dielectric constant value of the calcined samples which is equal to 153419 and 18957 at 950 <sup>°</sup>C and 1050 <sup>0</sup>C respectively. The complex impedance analysis of all samples shows a decrease in resistance with an increasing temperature, which suggests a semiconductor nature of the samples.</span></p>

Magnetoelectric effect and complex impedance analysis of (x)CoFe2O4+(1−x)Ba0.8Sr0.2TiO3 multiferroics

2009 ◽  
Vol 481 (1-2) ◽  
pp. 781-785 ◽  
Author(s):  
C.M. Kanamadi ◽  
J.S. Kim ◽  
H.K. Yang ◽  
B.K. Moon ◽  
B.C. Choi ◽  
...  
Keyword(s):  
Magnetoelectric Effect ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Complex Impedance Analysis

Electric–dielectric properties and complex impedance analysis of La0.5Ca0.5−xAgxMnO3 manganites

RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2177-2184 ◽  
Author(s):  
M. Smari ◽  
H. Rahmouni ◽  
N. Elghoul ◽  
I. Walha ◽  
E. Dhahri ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Spectroscopy Technique ◽  
Complex Impedance Analysis ◽  
Impedance Spectroscopy Technique

The electric and dielectric properties of La0.5Ca0.5−xAgxMnO3 (LCMO–Ag with x = 0 and x = 0.4) were investigated using the impedance spectroscopy technique.

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