Effects of Sr and Ni-Dopants on the Structure and Conductivity of Lanthanum Chromite

2010 ◽  
Vol 93-94 ◽  
pp. 558-561
Author(s):  
Anuchit Ruangvittayanon ◽  
Sutin Kuharuangrong
Keyword(s):  
Electrical Conductivity ◽  
Calcination Temperature ◽  
Perovskite Phase ◽  
Lanthanum Chromite ◽  
Chemical Compositions ◽  
Cold Isostatic Press ◽  
A Value ◽  
Maximum Conductivity ◽  
Icp Analysis

Compositions of lanthanum chromite substituted with Sr on the La site and Ni on the Cr site were synthesized by Citrate gel. The suitable calcination temperature of these compositions was 1100°C for 4 hrs to obtain a perovskite phase. The sample bars were formed by cold isostatic press and sintered at 1400°C for 5 hrs in air. The phase, microstructure, electrical conductivity were determined by XRD, dc four-probe as a function of temperature and their chemical compositions were identified by ICP analysis. The result of La0.9Sr0.1Cr0.5Ni0.5O3-δ shows the maximum conductivity of 72.76 Scm-1at 800°C in air. With further addition of Sr dopant, the conductivity of La0.8Sr0.2Cr0.5Ni0.5O3-δ decreases to a value of 54.98 Scm-1. In addition, the structure tends to change from orthorhombic to rhombohedral.

Influence of Cr deficiency on sintering, thermal expansion and electrical properties of La0.75Sr0.25Cr1−xO3−δ as a SOFC interconnect material

2016 ◽  
Vol 30 (11) ◽  
pp. 1650127 ◽  
Author(s):  
Yi Ren ◽  
Wen Ma ◽  
Xiaoying Li ◽  
Jun Wang ◽  
Yu Bai ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Electrical Properties ◽  
Perovskite Phase ◽  
Ignition Process ◽  
Thermal Expansion Coefficients ◽  
Auto Ignition ◽  
Pure Perovskite Phase ◽  
Maximum Conductivity ◽  
Expansion Coefficients ◽  
Interconnect Material

The SOFC interconnect materials La[Formula: see text]Sr[Formula: see text]Cr[Formula: see text]O[Formula: see text] [Formula: see text]–[Formula: see text] were prepared using an auto-ignition process. The influences of Cr deficiency on their sintering, thermal expansion and electrical properties were investigated. All the samples were pure perovskite phase after sintering at 1400[Formula: see text]C for 4 h. The cell volume of La[Formula: see text]Sr[Formula: see text]Cr[Formula: see text]O[Formula: see text] decreased with increasing Cr deficient content. The relative density of the sintered bulk samples increased from 93.2% [Formula: see text] to a maximum value of 94.7% [Formula: see text] and then decreased to 87.7% [Formula: see text]. The thermal expansion coefficients of the sintered bulk samples were in the range of [Formula: see text]–[Formula: see text] (30–1000[Formula: see text]C), which are compatible with that of YSZ. Among the investigated samples, the sample with 0.02 Cr deficiency had a maximum conductivity of 40.4 Scm[Formula: see text] and the lowest Seebeck coefficient of 154.8 [Formula: see text]VK[Formula: see text] at 850[Formula: see text]C in pure He. The experimental results indicate that La[Formula: see text]Sr[Formula: see text]Cr[Formula: see text]O[Formula: see text] has the best properties and is much suitable for SOFC interconnect material application.

The Influence of Silicon Dopant and Processing on Thermoelectric Properties of B4C Ceramics

1998 ◽  
Vol 545 ◽  
Author(s):  
Ke-Feng Cai ◽  
Ce-Wen Nan ◽  
Xin-Min Min
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Figure Of Merit ◽  
Room Temperature ◽  
A Value ◽  
Si Doped

AbstractB4C ceramics doped with various content of Si (0 to 2.03 at%) are prepared via hot pressing. The composition and microstructure of the ceramics are characterized by means of XRD and EPMA. Their electrical conductivity and Seebeck coefficient of the samples are measured from room temperature up to 1500K. The electrical conductivity increases with temperature, and more rapidly after 1300K; the Seebeck coefficient of the ceramics also increases with temperature and rises to a value of about 320μVK−1. The value of the figure of merit of Si-doped B4C rises to about 4 × 10−4K−1 at 1500K.

scholarly journals Electromagnetic Shielding Effectiveness of Woven Fabrics with High Electrical Conductivity: Complete Derivation and Verification of Analytical Model

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1657 ◽  
Author(s):  
Marek Neruda ◽  
Lukas Vojtech
Keyword(s):  
Electrical Conductivity ◽  
Analytical Model ◽  
Electromagnetic Interference ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
High Electrical Conductivity ◽  
Shielding Effectiveness ◽  
Textile Composite ◽  
A Value ◽  
Electromagnetic Shielding Effectiveness

In this paper, electromagnetic shielding effectiveness of woven fabrics with high electrical conductivity is investigated. Electromagnetic interference-shielding woven-textile composite materials were developed from a highly electrically conductive blend of polyester and the coated yarns of Au on a polyamide base. A complete analytical model of the electromagnetic shielding effectiveness of the materials with apertures is derived in detail, including foil, material with one aperture, and material with multiple apertures (fabrics). The derived analytical model is compared for fabrics with measurement of real samples. The key finding of the research is that the presented analytical model expands the shielding theory and is valid for woven fabrics manufactured from mixed and coated yarns with a value of electrical conductivity equal to and/or higher than σ = 244 S/m and an excellent electromagnetic shielding effectiveness value of 25–50 dB at 0.03–1.5 GHz, which makes it a promising candidate for application in electromagnetic interference (EMI) shielding.

Thermoelectric Properties of n-type (Bi2Se3)x(Bi2Te3)1-x Crystals Prepared by Zone Melting

2008 ◽  
Vol 368-372 ◽  
pp. 547-549
Author(s):  
Jun Jiang ◽  
Ya Li Li ◽  
Gao Jie Xu ◽  
Ping Cui ◽  
Li Dong Chen
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Zone Melting ◽  
Chemical Compositions ◽  
Melting Method ◽  
Temperature Range

In the present study, n-type (Bi2Se3)x(Bi2Te3)1-x crystals with various chemical compositions were fabricated by the zone melting method. Thermoelectric properties, including Seebeck coefficient (α), electrical conductivity (σ) and thermal conductivity (κ), were measured in the temperature range of 300-500 K. The influence of the variations of Bi2Te3 and Bi2Se3 content on thermoelectric properties was studied. The increase of Bi2Se3 content (x) caused an increase in carrier concentration and thus an increase of σ and a decrease of α. The maximum figure of merit (ZT = α2σT/κ) of 0.87 was obtained at about 325 K for the composition of 93%Bi2Te3-7%Bi2Se3 with doping TeI4.

Synthesis and Electrical Conductivity of N-(3-(Trifluoromethyl)Benzylidine)Thiosemicarbazide towards Dyes Sensitized Solar Cell

2018 ◽  
Vol 382 ◽  
pp. 364-368
Author(s):  
Uwaisulqarni M. Osman ◽  
Azieda Syafika N. Farizal ◽  
Nurhayati Ishak ◽  
Mohd Hasmizam Razali ◽  
M.I.N. Isa
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Light Intensity ◽  
Indium Tin Oxide ◽  
Spectroscopic Technique ◽  
Ito Glass ◽  
Maximum Conductivity ◽  
Ft Ir ◽  
Uv Visible ◽  
Conductivity Of Thin Films

Organic compound containing thiosemicarbazide moiety has been successfully synthesized. The new synthesized dyes, N-(3-(Trifluoromethylbenzaldehyde)benzylidine thiosemi- carbazide (3-TFT) was characterized by spectroscopic technique namely, CHNS elemental analysis, Fourier Transform Infra-Red analysis (FT-IR), UV-Visible analysis (UV-Vis),1H and13C Nuclear Magnetic Resonance (NMR). The thin films of this dye have been prepared using a spin coating technique and deposited on indium tin oxide (ITO) glass substrate. The main highlight was an electrical conductivity of thin films which was measured using four point probing system in a range of light intensity, 25 Wm-2until 200Wm-2. The potential electrical conductivity of 3-TFT dye was found gradually increased until reached the maximum conductivity values of 0.1489 Scm-1at light intensity of 100 Wm-2in the most diluted concentration at 1x10-5M.

scholarly journals Effect of ractopamine on physicochemical characteristics and collagen solubility in finishing pigs

2018 ◽  
Vol 192 ◽  
pp. 03054
Author(s):  
Chanporn Chaosap ◽  
Krongkaew Kaewthaworn ◽  
Ronachai Sitthigripong ◽  
Panneepa Sivapirunthep ◽  
Kamon Chaweewan
Keyword(s):  
Shear Force ◽  
Glycogen Content ◽  
Physicochemical Characteristics ◽  
Average Weight ◽  
Chemical Compositions ◽  
Finishing Pigs ◽  
Large White ◽  
Insoluble Collagen ◽  
A Value ◽  
Crossbred Pigs

The objective of this study was to investigate physicochemical characteristics and collagen solubility of pigs fed with dietary ractopamine (RAC) during finishing period. Thirty of three-way crossbred pigs (Large White × Landrace × Duroc) with an initial bodyweight (BW) of 18.0 ± 0.5 kg were randomly assigned to one to three dietary RAC inclusions (0, 20, or 40 mg/kg) fed during finishing period (60-100 kg BW). Each group consisted of five gilts and five barrows. After 109 day of raising period, all pigs were slaughtered at the average weight of 100 kg. Longissimus dorsi muscle (LD) was taken from each carcass after overnight chill and analyzed for physical characteristics, chemical composition, and collagen solubility. The LD from pigs fed 40 mg/kg of RAC had lower a* value (p < 0.01) than others. Pigs fed with 40 mg/kg of RAC had higher Warner-Bratzler shear force (p < 0.05) than pigs fed without RAC. Pigs fed with dietary RAC had lower glycogen content than control (p < 0.01). While other chemical compositions and collagen solubility of LD were not affected by dietary RAC (p > 0.05). Gilts had larger muscle fibers (p < 0.01), lower glycogen content (p < 0.05), higher content of insoluble collagen (p < 0.05), total collagen (p = 0.054), and collagen solubility (p = 0.054) than barrows.

scholarly journals Development of Pressure-Responsive PolyPropylene and Biochar-Based Materials

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 339 ◽  
Author(s):  
Amir Noori ◽  
Mattia Bartoli ◽  
Alberto Frache ◽  
Erik Piatti ◽  
Mauro Giorcelli ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Plastic Deformation ◽  
Electrical Properties ◽  
Tea Leaves ◽  
Scanning Calorimetry ◽  
A Value ◽  
Wide Range ◽  
Order Of Magnitude

In this research paper, we reported the synthesis of biochar-based composites using biochar derived from exhausted tea leaves and polypropylene. The resulting materials were deeply characterized investigating mechanical (dynamic mechanical thermal analysis), thermal (thermogravimetrical analysis and differential scanning calorimetry), morphological (field emission scanning microscopy) and electrical properties vs. temperature. Furthermore, electrical conductivity was studied for a wide range of pressures showing an irreversible plastic deformation. An increment of one order of magnitude in the conductivity was observed in the case of 40 wt% biochar loading, reaching a value of 0.2 S/m. The material produced exhibited the properties of an irreversible pressure sensor.

Electrical Conductivity of Y3+ Doped Ba(Ce,Zr)O3 in Wet N2 Atmosphere Prepared with the Addition of Brij-97

2020 ◽  
Vol 307 ◽  
pp. 160-165
Author(s):  
Nur Syafkeena Mohd Affandi ◽  
Nafisah Osman ◽  
Oskar Hasdinor Hassan
Keyword(s):  
Grain Size ◽  
Calcination Temperature ◽  
Electrochemical Impedance ◽  
Perovskite Phase ◽  
Total Conductivity ◽  
Processing Temperature ◽  
Barium Cerate ◽  
Electrical Measurements ◽  
Ceramic Oxide ◽  
Brij 97

Y-doped barium cerate-zirconate ceramic oxide is proven to be a competent material as an electrolyte with high proton conductivity as well as chemical and mechanical stabilities in carbon dioxide and water vapour atmospheres. This ceramic oxide requires high processing temperature which will results in the increase of particle/grain size. Hence, modification on the synthesis route has been studied in reducing the particle/grain size of the ceramic by lowering the calcination temperature. In this work, BaCe0.54Zr0.36Y0.1O2.95 (BCZY) powder was synthesized with addition of surfactant (Brij-97) through an established modified sol-gel route. Single BCZY perovskite phase was successfully obtained at calcination temperature of 950°C which was lower than our previous study (T=1100°C). The prepared sample was made into pellet by a dry pressing technique with diameter, d=13 mm and thickness, t~2 mm and then subjected to a two-step sintering method prior to morphological and electrical measurements. Impedance measurement was carried out at intermediate temperatures (500-800°C) using an Electrochemical Impedance Spectroscopy (EIS) in wet nitrogen atmosphere. Impedance spectrum was analysed to obtain the behaviour of grain core and grain boundary responses by a fitting procedure using a brick-layer model. Scanning electron microscope (SEM) analysis of fractured pellet revealed that BCZY prepared with the assisted of Brij-97 exhibited dense, homogenous and less agglomerate grain with grain size around 88 nm, which may explain the enhancement in the total conductivity of the BCZY electrolyte.

Experimental Investigations of Ni Nanoparticle-Polyurethane Acrylic Composite for Electrical Conductivity Enhancement

MRS Advances ◽  
2019 ◽  
Vol 4 (43) ◽  
pp. 2337-2344
Author(s):  
Adrian Goodwin ◽  
Ajit D. Kelkar ◽  
Ram V. Mohan
Keyword(s):  
Electrical Conductivity ◽  
Nickel Nanoparticles ◽  
Surface Concentration ◽  
Nano Particles ◽  
Experimental Investigations ◽  
Conductivity Measurements ◽  
Conductivity Enhancement ◽  
Conductive Composites ◽  
Maximum Conductivity ◽  
Number Of Particles

ABSTRACTConductive composites are being considered for use in applications such as electromagnetic shielding. Prior work has shown correlation of electrical conductivity to the microstructure of corresponding composite. In the present paper, composites consisting of polyurethane acrylic and dispersed nickel nanoparticles were fabricated, and tested for their electrical conductivity. In the fabrication process, half of the suspensions were agitated by sonication and half were not. Correlations between electrical conductivity and composite microstructural details are presented. These correlations show an optimum concentration of nickel nanoparticles that result in maximum conductivity enhancement. In addition, sonicating the suspensions increased conductivity of resulting nanocomposites. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) images were used to estimate surface concentration and distribution of Nickel nanoparticles, and were correlated to electrical conductivity measurements. Parameters such as number of particles in contact and junction distance between the nano particles in the composites are suggested as a way of enhancing electrical conductivity.

Determination of frost hardiness of Eucalyptus using the electrical conductivity of diffusate in conjunction with a freezing chamber

1988 ◽  
Vol 18 (5) ◽  
pp. 595-600 ◽  
Author(s):  
P. M. Hallam ◽  
W. N. Tibbits
Keyword(s):  
Electrical Conductivity ◽  
Frost Hardiness ◽  
Lethal Temperature ◽  
Conductivity Method ◽  
Water Conductivity ◽  
Leaf Discs ◽  
Significant Difference ◽  
Maximum Conductivity ◽  
Electrical Conductivity Method

An electrical conductivity method for determining frost hardiness of tissue discs punched from Eucalyptus leaves is described. Samples were exposed to convective heat loss in an air-filled chamber. Rates of cooling and desired frost temperatures were electronically controlled and maintained. Supercooling of tissue was effectively eliminated by addition of small amounts of AgI and water. Conductivity of diffusate was measured as a means of quantifying tissue damage following frost. Relative conductivity was determined with reference to subsequent measurements following heating the discs to 70 °C which resulted in maximum conductivity. Exposure of leaf discs to temperatures below the lethal temperature for these species (<−10 °C) resulted in similar maximum conductivity readings. The technique is evaluated to assess its potential to distinguish small differences in frost hardiness caused by genotype and environment. For both E. delegatensis and E. nitens there was no significant difference in frost hardiness expressed in terms of mean lethal temperature when comparing leaf discs with frosting whole seedlings.

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