Dielectric characteristics of Fe-doped LaTiO3+δ and visible light modulation

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101571-101577 ◽  
Author(s):  
Yan Chen ◽  
Yimin Cui ◽  
Jun-en Yao
Keyword(s):  
Dielectric Properties ◽  
Visible Light ◽  
Room Temperature ◽  
Light Modulation ◽  
Frequency Range ◽  
Reaction Route ◽  
Dielectric Characteristics ◽  
Ceramic Samples ◽  
Solid State Reaction Route ◽  
Measured Frequency Range

Fe-doped La1−xFexTiO3+δ (x = 0.05, 0.1, and 0.3, 0.4) ceramic samples were prepared via traditional solid-state reaction route, in which the dielectric properties of visible light modulation were found at room temperature in the measured frequency range.

scholarly journals Effects of V2O5 Additive on Structure and Dielectric Properties of BiNbO4 Ceramics

2013 ◽  
Vol 58 (4) ◽  
pp. 1387-1390
Author(s):  
A. Lisińska-Czekaj ◽  
D. Czekaj ◽  
K. Osińska ◽  
M. Adamczyk
Keyword(s):  
Dielectric Properties ◽  
Complex Impedance ◽  
Pressureless Sintering ◽  
Relaxation Phenomena ◽  
Frequency Range ◽  
Reaction Route ◽  
X Ray ◽  
Dielectric Characterization ◽  
Frequency Domains ◽  
Solid State Reaction Route

Abstract Goal of the present research was to investigate the influence of V2O5 additive on the structure and dielectric properties of BiNbO4 ceramics. To fabricate BiNbO4 ceramics with V2O5 added the solid state reaction route and pressureless sintering was utilized. Thus obtained ceramics was characterized in terms of its microstructure (SEM), chemical composition (EDS), phase composition and crystalline structure (X-ray phase and structural analysis, respectively). Also dielectric properties in both temperature and frequency domains were investigated. The impedance spectroscopy was utilized for dielectric characterization and the measurements of complex impedance were performed within the frequency range ν =10Hz-1MHz and temperature range T =RT-550°C. It was found that V2O5 additive changed slightly lattice parameters of BiNbO4 ceramics, decreased porosity of samples and revealled relaxation phenomena within the frequency ranges ν =102-103 Hz and ν =105-106 Hz at temperature T>285°C.

Influence of Phase Composition on Dielectric Properties of Bismuth-Based Ceramics with Scheelite-Type Structure

2014 ◽  
Vol 602-603 ◽  
pp. 683-688
Author(s):  
Dionizy Czekaj ◽  
Agata Lisińska-Czekaj
Keyword(s):  
Phase Composition ◽  
Dielectric Properties ◽  
Solid State ◽  
Pressureless Sintering ◽  
Dielectric Losses ◽  
Frequency Range ◽  
Minor Phase ◽  
Reaction Route ◽  
Excess Amount ◽  
Solid State Reaction Route

Goal of the present research was to study dielectric properties of BiNbO4 ceramics fabricated by solid state reaction route followed with pressureless sintering. The samples were fabricated from the mixture of oxides, viz. Nb2O5 and Bi2O3. Apart from stoichiometric amount an excess of 3%, 5% and 10% by mole of Bi2O3 was used. It was found that an excess amount of Bi2O3 oxide caused formation of Bi5Nb3O15 minor phase in amount of 9wt%, 18wt% and 25wt%, respectively. The dielectric properties were studied by impedance spectroscopy within the frequency range ν=20Hz1MHz and temperature range T=RT550°C. It was found that the presence of the minor phase in amount of 18wt% caused a decrease in dielectric losses of the material under studies.

Technology and Properties of (1-x)PZT-(x)PFW Ceramics with 0.25

2014 ◽  
Vol 605 ◽  
pp. 424-427 ◽  
Author(s):  
Ryszard Skulski ◽  
Ewa Nogas-Cwikiel ◽  
Dariusz Bochenek ◽  
Przemysław Niemiec ◽  
Paweł Wawrzała
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Ceramic Technology ◽  
Ceramic Samples

We present the results of obtaining and investigating ceramic samples of solid solution (1-x)(PbZr0.53Ti0.47O3)-x (PbFe2/3W1/3O3) [i.e. (1-x)PZT-xPFW] with x = 0.25, 0.35, 0.45 and 0.55 obtained from oxides using conventional ceramic technology. In this paper we present the results of investigations of XRD and main dielectric properties. For x = 0.25 and x = 0.35 we investigated also P-E hysteresis loops at room temperature.

Bifunctional gas sensor based on Bi2S3/SnS2 heterostructures with improved selectivity through visible light modulation

2022 ◽  
Author(s):  
Tingting Wang ◽  
Juanyuan Hao ◽  
Jiaying Liu ◽  
Yanling Zhang ◽  
Qihua Liang ◽  
...  
Keyword(s):  
Internet Of Things ◽  
Visible Light ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Room Temperature ◽  
The Internet ◽  
Light Modulation ◽  
Sensing Platform ◽  
Hazardous Gases ◽  
The Internet Of Things

Effective monitoring of hazardous gases at room-temperature is extremely indispensable in the “Internet of things” application; however, developing bifunctional gas sensors for the advanced sensing platform still remains a challenge....

scholarly journals Influence of Nd Substitution by La in on Structural and Transport Properties for Sensing Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Sudarshan Vadnala ◽  
Saket Asthana ◽  
Prem Pal ◽  
S. Srinath
Keyword(s):  
Transport Properties ◽  
Room Temperature ◽  
Parent Compound ◽  
Theoretical Models ◽  
Maximum Temperature ◽  
Structural Form ◽  
Reaction Route ◽  
Temperature Coefficients ◽  
Sensing Applications ◽  
Solid State Reaction Route

The structural and transport properties of manganites with and 0.2 prepared by solid state reaction route are studied. These compounds are found to be crystallized in orthorhombic structural form. A shift in the metal-semiconductor/insulator transition temperature () towards room temperature (289 K) with the substitution of Nd by La, as the value of is varied in the sequence (0, 0.1, and 0.2), has been provided. The shift in the , from 239 K (for ) to near the room temperature 289 K (for ), is attributed to the fact that the average radius of site-A increases with the percentage of La. The maximum temperature coefficients of resistance (TCR) of ( and 0.2) are found to be higher compared to its parent compound which is almost independent of . The electrical resistivity of the experimental results is explored by various theoretical models below and above . An appropriate enlightenment for the observed behavior is discussed in detail.

Anisotropic Permittivity Measurement of Layered Inorganic Compounds

2011 ◽  
Vol 492 ◽  
pp. 168-171
Author(s):  
Hong Ya Wu ◽  
Ji Zhou
Keyword(s):  
Dielectric Properties ◽  
Room Temperature ◽  
Inorganic Compounds ◽  
Frequency Range ◽  
Impedance Analyzer ◽  
Anisotropic Dielectric ◽  
Permittivity Measurement

The anisotropic permittivity of fluorophlogopite and biotite was measured as a function of frequency in directions along and perpendicular to the cleavage planes. The measurements were performed using an impedance analyzer in the frequency range between 0.01MHz and 10MHz at room temperature. Micas showed anisotropic dielectric properties and the anisotropy of biotite was stronger than fluorophlogopite. The permittivity reduced with the increase of frequency. These properties depended on the structure, composition and defects of micas.

scholarly journals Impedance Spectroscopy (BeO+TiO2)-Ceramics with Additive of TiO2 Nanoparticles

2019 ◽  
pp. 366-380
Author(s):  
Anatoliy A. Lepeshev ◽  
Alexandr V. Pavlov ◽  
Nikolai A. Drokin
Keyword(s):  
Impedance Spectroscopy ◽  
High Frequency ◽  
Microwave Field ◽  
Frequency Range ◽  
Nanocrystalline Tio2 ◽  
Electrically Conductive ◽  
Dielectric Characteristics ◽  
Ceramic Samples ◽  
Static Resistance ◽  
First Time

The present study is aimed at obtaining electrically conductive two-component ceramics based on BeO with the addition of micro and nanocrystalline TiO2 powder. The ceramics of the composition (BeO+TiO2) is used in radio-electronic equipment as effective absorbers of microwave radiation and in other areas of modern electronics. The nature of the appearance of electrical conductivity and absorption of the microwave field in (BeO+TiO2) ceramics has not been completely established. The impedance spectroscopy method for the first time investigated the electrical and dielectric characteristics of this ceramics in the frequency range from 100 Hz to 100 MHz, depending on the presence of micro and nano-sized TiO2 phases in the composition of the BeO ceramics. It was established that the static resistance of ceramics with the addition of titanium oxide nanopowder is significantly reduced compared with the resistance of the original ceramics with TiO2 micropowder. It is shown that the real and imaginary components of the dielectric constant of the studied ceramics increase to abnormally large values when the frequency of the effective electric field decreases, and in the high frequency range f ≥ 108 Hz, the process of dielectric relaxation begins, leading to an increase in the dielectric loss tangent. The dielectric characteristics of these ceramic samples under conditions of blocking through conduction are determined

scholarly journals Permittivity and modulus spectroscopic study of BaFe0.5Nb0.5O3 ceramics

2013 ◽  
Vol 7 (4) ◽  
pp. 181-187 ◽  
Author(s):  
Subrat Kar ◽  
Pawan Kumar
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Perovskite Phase ◽  
Space Charge Polarization ◽  
Reaction Route ◽  
Conventional Solid State Reaction ◽  
Polarization Model ◽  
Single Perovskite Phase ◽  
Solid State Reaction Route ◽  
C Complex

Ba(Fe0.5Nb0.5)O3 (BFN) powder was synthesized in single perovskite phase by conventional solid state reaction route and BFN ceramic was obtained by uniaxial pressing and sintering at 1350?C. Complex immittance like: permittivity and modulus spectroscopic formalism were simultaneously used to explain dielectric behaviour of the ceramics. The activation energy calculated from dielectric relaxation below 100?C was found to be ~ 0.19 eV. The activation energy obtained from modulus spectra above 100?C was ~0.59 eV. The space charge polarization model was used to explain the origin of relaxation and ?giant? permittivity of BFN ceramics near room temperature.

Conductivity studies of Ni and Gd substituted BiCoO3

2014 ◽  
Vol 28 (05) ◽  
pp. 1450034 ◽  
Author(s):  
T. Ramachandran ◽  
N. E. Rajeevan ◽  
P. P. Pradyumnan
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Structural Studies ◽  
Reaction Route ◽  
Low Thermal Conductivity ◽  
Sem Micrograph ◽  
New Material ◽  
Cubic Structure ◽  
Solid State Reaction Route ◽  
Room Temperature Raman Spectrum

In this paper, we report the synthesis, thermal and electrical property studies of Ni 0.5 Gd 0.2 Bi 0.3 CoO 3, a new material for thermoelectric applications. The material was synthesized by solid state reaction route taking BiCoO 3 as basic matrix by substituting bismuth with nickel and gadolinium. Structural studies using room temperature XRD and room temperature Raman spectrum established cubic structure for Ni 0.5 Bi 0.5 CoO 3 and tetragonal structure for Ni 0.5 Gd 0.2 Bi 0.3 CoO 3. The SEM micrograph of the samples revealed crystallites of micrometer dimension with varying grain size. The sample showed interestingly low thermal conductivity and VRH mechanism was found to dominate in the electrical conduction at low temperature regime. The low thermal conductivity and moderate electrical conductivity is suggestive of strong candidature of the material for thermoelectric applications.

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