Preparation and Electrical Properties of Ba2TiOSi2−xGexO7 (x=0.0 and 0.2) Ferroelectric Ceramics

Magnetite nanoparticles have been prepared by using sol-gel auto combustion technique. The samples are prepared by using different concentrations of fuel. Structural characterization has been done using X-Ray diffraction technique and it was observed that fuel concentration can affect the structural properties of Magnetite nanoparticles. The dielectric properties for all the samples such as dielectric constant (??), dielectric tangent loss (tan ?) and dielectric loss factor (??) have been studied as a function of frequency and temperature in the range 10 Hz20 MHz and it was found that these nanoparticles can be used in microwave devices because of their good dielectric behavior. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i3.17938 J. Sci. Res. 6 (3), 399-406 (2014)

Download Full-text

Study of the structure and dielectric relaxation behavior of Pb(Mg1/3Nb2/3)O3–PbTiO3 ferroelectric ceramics

Journal of Materials Research ◽

10.1557/jmr.1999.0620 ◽

1999 ◽

Vol 14 (12) ◽

pp. 4581-4586 ◽

Cited By ~ 28

Author(s):

Xiaowen Zhang ◽

Fei Fang

Keyword(s):

Phase Boundary ◽

Phase Region ◽

Dielectric Behavior ◽

Ferroelectric Ceramics ◽

X Ray Diffraction ◽

Precursor Method ◽

Two Phase ◽

X Ray ◽

Dielectric Relaxation Behavior ◽

Columbite Precursor

(1–x)PMN–xPT[PMN, Pb(Mg1/3Nb2/3)O3; PT, PbTiO3] system ferroelectric ceramics with x = 0.30, 0.33, 0.35, and 0.38 were synthesized by the columbite precursor method. Their structure and dielectric behavior were investigated. X-ray diffraction results demonstrate that no two-phase region is presented, but a quasi-cubic to tetragonal phase boundary lies between x = 0.30 and 0.33. Examination of the dielectric behavior reveals that the transformation from relaxor to normal ferroelectric behavior across the morphotropic phase boundary (MPB) is successive and continuous. It is suggested that x 4 0.30 to 0.33 is the composition of MPB for the PMN–PT system. The MPB is also a boundary for the PMN–PT system to transform from relaxor to normal ferroelectrics.

Download Full-text

Electrical Properties of (1–x)(0.8PMN-0.2PNN)-xPT Ceramics near the Morphotropic Phase Boundary

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.18 ◽

2007 ◽

Vol 336-338 ◽

pp. 18-20

Author(s):

Guo Yuan Zhou ◽

Jin Song Pan ◽

Xiao Wen Zhang

Keyword(s):

Phase Boundary ◽

Morphotropic Phase Boundary ◽

Piezoelectric Properties ◽

Dielectric Behavior ◽

Dielectric Constants ◽

Ferroelectric Ceramics ◽

X Ray Diffraction ◽

Precursor Method ◽

High Dielectric ◽

Columbite Precursor

Ferroelectric ceramics of (1x)(0.8PMN0.2PNN)xPT (x = 0.280.43) were synthesized by the columbite precursor method. Their phase structures as well as the dielectric, ferroelectric and piezoelectric properties were investigated. X-ray diffraction (XRD) results demonstrate that the morphotropic phase boundary (MPB) of this system lies in the composition range of x = 0.31–0.37. Examination of the dielectric behavior indicates that the ceramics exhibit high dielectric constants near the MPB compositions. In addition, the piezoelectric properties of the ceramics were found quite well around the MPB. The interrelated mechanism was also discussed.

Download Full-text

Temperature dependent single crystal X-ray diffraction study of the T∗ phase compound (La1.20Tb0.72Pb0.08)CuO4

Journal of the Less Common Metals ◽

10.1016/0022-5088(90)90485-3 ◽

1990 ◽

Vol 164-165 ◽

pp. 792-799 ◽

Cited By ~ 2

Author(s):

P. Bordet ◽

J.J. Capponi ◽

C. Chaillout ◽

S-W. Cheong ◽

J. Chenavas ◽

...

Keyword(s):

Single Crystal ◽

Diffraction Study ◽

X Ray Diffraction ◽

Temperature Dependent ◽

X Ray ◽

Phase Compound ◽

T Phase

Download Full-text

Preparation and Characterization of Dielectric Behavior of A2/3Cu3Ti4O12 (A = Nd, Sm, Gd, Dy) Ceramics

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.67.28 ◽

2010 ◽

Vol 67 ◽

pp. 28-33 ◽

Cited By ~ 3

Author(s):

Dorota Szwagierczak ◽

Jan Kulawik

Keyword(s):

Single Phase ◽

Elevated Temperatures ◽

Relaxation Times ◽

Dielectric Behavior ◽

X Ray Diffraction ◽

Conventional Solid State Reaction ◽

Low Frequencies ◽

Perovskite Materials ◽

Very High

In this work perovskite materials A2/3Cu3Ti4O12 (where A=Nd, Sm, Gd, Dy) were synthesized by conventional solid state reaction and sintered at 1000-1100°C. X-ray diffraction analysis confirmed single-phase composition of the investigated ceramics. Dielectric properties of the samples were investigated in the temperature range from -55 to 300°C at frequencies 10 Hz – 2 MHz. Dielectric permittivities of the ceramics are very high, exceeding 105 at low frequencies and/or elevated temperatures (above 50°C) and 103 at higher frequencies and/or low temperatures. Two observed contributions to the dielectric response are attributed to semiconducting grains and more resistive grain boundaries. For Nd2/3Cu3Ti4O12 and Sm2/3Cu3Ti4O12 ceramics, the observed low- and high frequency plateaus are lower than those for Gd2/3Cu3Ti4O12 and Dy2/3Cu3Ti4O12. The relaxation times determined on the basis of impedance data were found to decrease with increasing atomic number of lanthanide. The analysis of the impedance spectroscopic data and the microstructure implies spontaneous formation of internal barrier layer capacitors in the investigated materials.

Download Full-text

The mechanism for the enhanced piezoelectricity in multi-elements doped (K,Na)NbO3 ceramics

Nature Communications ◽

10.1038/s41467-021-21202-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xiaoyi Gao ◽

Zhenxiang Cheng ◽

Zibin Chen ◽

Yao Liu ◽

Xiangyu Meng ◽

...

Keyword(s):

High Performance ◽

Functional Materials ◽

Atomic Scale ◽

Ferroelectric Ceramics ◽

Structure Property ◽

X Ray Diffraction ◽

Temperature Dependent ◽

Transmission Electron ◽

Scanning Transmission ◽

High Dielectric

Abstract(K,Na)NbO3 based ceramics are considered to be one of the most promising lead-free ferroelectrics replacing Pb(Zr,Ti)O3. Despite extensive studies over the last two decades, the mechanism for the enhanced piezoelectricity in multi-elements doped (K,Na)NbO3 ceramics has not been fully understood. Here, we combine temperature-dependent synchrotron x-ray diffraction and property measurements, atomic-scale scanning transmission electron microscopy, and first-principle and phase-field calculations to establish the dopant–structure–property relationship for multi-elements doped (K,Na)NbO3 ceramics. Our results indicate that the dopants induced tetragonal phase and the accompanying high-density nanoscale heterostructures with low-angle polar vectors are responsible for the high dielectric and piezoelectric properties. This work explains the mechanism of the high piezoelectricity recently achieved in (K,Na)NbO3 ceramics and provides guidance for the design of high-performance ferroelectric ceramics, which is expected to benefit numerous functional materials.

Download Full-text

Phase transition in Bi8Fe6Ti3O27 multiferroic ceramics

Open Physics ◽

10.2478/s11534-008-0064-7 ◽

2008 ◽

Vol 6 (3) ◽

Cited By ~ 2

Author(s):

Sunanda Patri ◽

Ram Choudhary

Keyword(s):

Remanent Polarization ◽

Single Phase ◽

Microstructural Analysis ◽

Elemental Content ◽

X Ray Diffraction ◽

Temperature Dependent ◽

Orthorhombic Crystal ◽

Solid State Reaction Technique ◽

X Ray ◽

Phase Compound

AbstractThe polycrystalline Bi8Fe6Ti3O27 compound was prepared by a high-temperature solid-state reaction technique. Preliminary structural analysis by X-ray diffraction (XRD) confirms the formation of a single-phase compound in an orthorhombic crystal system at room temperature. The elemental content of the compound was analyzed by EDAX microanalysis. Microstructural analysis by scanning electron microscopy (SEM) shows that the compound has well defined grains, which are distributed uniformly throughout the surface of the pellet sample. Detailed studies of temperature-dependent dielectric response at various frequencies show dielectric anomalies at 380, 389 and 403°C for 10 kHz, 100 kHz, and 1 MHz respectively. The hysteresis loop observed by applying an electric field of 12 kV/cm on the poled sample with smaller remanent polarization supports the existence of ferroelectricity in this material. The value of d33 of the compound was found to be 19 pC/N.

Download Full-text

STRUCTURAL AND DIELECTRIC PROPERTIES OF Ba2Sr3SmTi3V7O30

Modern Physics Letters B ◽

10.1142/s0217984908017448 ◽

2008 ◽

Vol 22 (30) ◽

pp. 2999-3005 ◽

Cited By ~ 8

Author(s):

P. S. SAHOO ◽

S. K. PATRI ◽

R. N. P. CHOUDHARY ◽

A. PANIGRAHI

Keyword(s):

Activation Energy ◽

Single Phase ◽

Tungsten Bronze ◽

Polycrystalline Sample ◽

Tangent Loss ◽

X Ray Diffraction ◽

Solid State Reaction Technique ◽

X Ray ◽

Phase Compound ◽

Grain Distribution

The polycrystalline sample of Ba 2 Sr 3 SmTi 3 V 7 O 30, a member of the tungsten bronze structural family, was prepared by a high-temperature solid-state reaction technique. Preliminary X-ray diffraction analysis suggests the formation of a single-phase compound with orthorhombic structure. Detailed studies of the dielectric constant and tangent loss as a function of frequency (100 Hz to 1 MHz) and temperature (32°–500°C) show that this compound has a diffused-type of ferroelectric phase transition at 230°C. Study of the surface morphology by SEM showed uniform grain distribution on the surface of the sample with less porosity. The activation energy, calculated from the plot of temperature dependence of AC conductivity, of the compound was found to be 0.11 eV and 0.14 eV at 500 kHz and 1 MHz respectively. The nature of the variation of conductivity and value of activation energy suggest that the conduction process is of a mixed-type.

Download Full-text

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

10.26434/chemrxiv.9943961.v2 ◽

2019 ◽

Author(s):

Till Fuchs ◽

Sean Culver ◽

Paul Till ◽

Wolfgang Zeier

Keyword(s):

Ionic Conductivity ◽

Vacancy Concentration ◽

Sodium Ion ◽

High Ionic Conductivity ◽

Ionic Conductors ◽

X Ray Diffraction ◽

X Ray ◽

Solid State Batteries ◽

Ion Conducting ◽

Very High

The sodium-ion conducting family of Na3PnS4, with Pn = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na3PnS4, the solid solutions with WS42- introduction are explored. The influence of the substitution with WS42- for PS43- and SbS43-, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm-1 for Na2.9P0.9W0.1S4 and 41 ± 8 mS·cm-1 for Na2.9Sb0.9W0.1S4 can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.

Download Full-text

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

10.26434/chemrxiv.9943961.v1 ◽

2019 ◽

Author(s):

Till Fuchs ◽

Sean Culver ◽

Paul Till ◽

Wolfgang Zeier

Keyword(s):

Ionic Conductivity ◽

Vacancy Concentration ◽

Sodium Ion ◽

High Ionic Conductivity ◽

Ionic Conductors ◽

X Ray Diffraction ◽

X Ray ◽

Solid State Batteries ◽

Ion Conducting ◽

Very High

The sodium-ion conducting family of Na3PnS4, with Pn = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na3PnS4, the solid solutions with WS42- introduction are explored. The influence of the substitution with WS42- for PS43- and SbS43-, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm-1 for Na2.9P0.9W0.1S4 and 41 ± 8 mS·cm-1 for Na2.9Sb0.9W0.1S4 can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.

Download Full-text