Electrical conductivity increase by order of magnitude through controlling sintering to tune hierarchical structure of oxide ceramics

2020 ◽  
pp. 121831
Author(s):  
Sergio A. Paredes-Navia ◽  
Liang Liang ◽  
Cesar-Octavio Romo-De-La-Cruz ◽  
Ellena Gemmen ◽  
Andre Fernandes ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Hierarchical Structure ◽  
Oxide Ceramics ◽  
Electrical Conductivity Increase ◽  
Conductivity Increase ◽  
Order Of Magnitude

Evaluation of Electrical Characteristics for PMMA-TiO2 Nanocomposites Used in Dentistry

2018 ◽  
Vol 69 (1) ◽  
pp. 155-159 ◽  
Author(s):  
Eugenia Eftimie Totu ◽  
Elena Voicila ◽  
Vlad Pistritu ◽  
Gheorghe Nechifor ◽  
Corina Marilena Cristache
Keyword(s):  
Electrical Conductivity ◽  
Impedance Analysis ◽  
Dielectric Constants ◽  
Uv Exposure ◽  
Electrical Characteristics ◽  
Casting Method ◽  
Nano Tio2 ◽  
Electrical Conductivity Increase ◽  
Conductivity Increase ◽  
Electrical Conductivities

In this paper, it is studied the influence of TiO2 nanoparticles content (0.2-5% wt:wt) on the electrical conductivities and the dielectric constants of poly (methyl methacrylate) (PMMA) nanocomposites used for 3D printing in dentistry. The nanocomposites films, which have been obtained applying the casting method followed by UV exposure, were mounted in a four electrodes cell for the electrochemical a.c. impedance analysis. The experimental data showed that both the dielectric constant and the electrical conductivity increase with increasing amounts of nano-TiO2 in nanocomposites. However, the change in the electrical conductivity is not significant for less 1% nano-titania added.

scholarly journals Влияние электронного облучения на диэлектрические характеристики монокристаллов AgGaSe-=SUB=-2-=/SUB=-

2019 ◽  
Vol 61 (10) ◽  
pp. 1743
Author(s):  
А.У. Шелег ◽  
В.Г. Гуртовой
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electron Irradiation ◽  
Frequency Dispersion ◽  
Significant Frequency ◽  
Electrical Conductivity Increase ◽  
Conductivity Increase ◽  
Measuring Field ◽  
Dielectric Constant Decrease

The effect of various doses of electron irradiation on the dielectric constant and electrical conductivity of triple nonlinear AgGaSe2 crystals at different measuring field frequencies in the temperature range of 100-300 K has been investigated. It has been found that single-crystal irradiation leads to a dielectric constant decrease and an electrical conductivity significant increase. It is shown that the dielectric constant and electrical conductivity increase with an temperature increase. It has been established that AgGaSe2 crystals are characterized by the presence of several conductivity types. A significant frequency dispersion of the dielectric properties of the investigated crystals was found.

scholarly journals Thermal and Electrical Conductivity of Unsaturated Polyester Resin Filled with Copper Filler Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Kemal Yaman ◽  
Özer Taga
Keyword(s):  
Electrical Conductivity ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Filler Particle ◽  
Unsaturated Polyester Resin ◽  
Electrical Conductivity Increase ◽  
Conductivity Increase ◽  
Filler Particle Size ◽  
Polyester Matrix ◽  
Composite Mixture

Thermal and electrical conductivity of unsaturated polyester resin with copper filler composite material are investigated both theoretically and experimentally. In the experiments, polyester matrix is combined with dendrite-shape copper to determine the effects of both filler size and content on thermal and electrical conductivity, respectively. It is observed that the increase in the concentration causes the thermal and electrical conductivity of composite mixture to grow up. It has also been observed that the both thermal and electrical conductivity increase with increasing filler particle size.

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

Electrical Properties of Additively Manufactured Acrylonitrile Butadiene Styrene/Carbon Nanotube Nanocomposite

2018 ◽  
Author(s):  
Dominic Thaler ◽  
Nahal Aliheidari ◽  
Amir Ameli
Keyword(s):  
Electrical Conductivity ◽  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Functional Materials ◽  
Acrylonitrile Butadiene Styrene ◽  
Extrusion Process ◽  
Print Quality ◽  
Fused Deposition ◽  
Order Of Magnitude ◽  
Butadiene Styrene

Additive manufacturing is an emerging method to produce customized parts with functional materials without big investments. As one of the common additive manufacturing methods, fused deposition modeling (FDM) uses thermoplastic-based feedstock. It has been recently adapted to fabricate composite materials too. Acrylonitrile butadiene styrene (ABS) is the most widely used material as FDM feedstock. However, it is an electrically insulating polymer. Carbon Nanotubes (CNTs) on the other hand are highly conductive. They are attractive fillers because of their high aspect ratio, and excellent mechanical and physical properties. Therefore, a nanocomposite of these two materials can give an electrically conductive material that is potentially compatible with FDM printing. This work focuses on the investigation of the relationships between the FDM process parameters and the electrical conductivity of the printed ABS/CNT nanocomposites. Nanocomposite filaments with CNT contents up to 10wt% were produced using a twin-screw extruder followed by 3D printing using FDM method. The starting material was pellets from a masterbatch containing 15 wt% CNT. Compression-molded samples of ABS/CNT were also prepared as the bulk baselines. The effects of CNT content and nozzle size on the through-layer and in-layer electrical conductivity of the printed nanocomposites were analyzed. Overall, a higher percolation threshold was observed in the printed samples, compared to that of the compression-molded counterparts. This resulted in the conductivity of the printed samples that is at least one order of magnitude lower. Moreover, at CNT contents up to 5 wt%, the in-layer conductivity of the printed samples was almost two orders of magnitudes higher than that in the through-layer direction. In ABS/3 wt% CNT samples, the through-layer conductivity continuously decreased as the nozzle diameter was decreased from 0.8 mm to 0.35 mm. These variations in the electrical conductivity were explained in terms of the CNT alignment, caused by the extrusion process during the print, quality of interlayer bonding during deposition, and the voids created due to the discrete nature of the printing process.

scholarly journals SYNTHESIS AND ELECTRICAL CONDUCTIVITY OF SOLID SOLUTIONS OF THE SYSTEM RbF-PbF2-SnF2

2019 ◽  
Vol 85 (5) ◽  
pp. 60-68
Author(s):  
Yuliay Pogorenko ◽  
Anatoliy Omel’chuk ◽  
Roman Pshenichny ◽  
Anton Nagornyi
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Solid Solutions ◽  
Basic Structure ◽  
Elementary Cell ◽  
Initial Structure ◽  
Fluoride Ions ◽  
Temperature Range ◽  
Order Of Magnitude

In the system RbF–PbF2–SnF2 are formed solid solutions of the heterovalent substitution RbxPb0,86‑xSn1,14F4-x (0 < x ≤ 0,2) with structure of β–PbSnF4. At x > 0,2 on the X-ray diffractograms, in addition to the basic structure, additional peaks are recorded that do not correspond to the reflexes of the individual fluorides and can indicate the formation of a mixture of solid solutions of different composition. For single-phase solid solutions, the calculated parameters of the crystal lattice are satisfactorily described by the Vegard rule. The introduction of ions of Rb+ into the initial structure leads to an increase in the parameter a of the elementary cell from 5.967 for x = 0 to 5.970 for x = 0.20. The replacement of a part of leads ions to rubium ions an increase in electrical conductivity compared with β–PbSnF4 and Pb0.86Sn1.14F4. Insignificant substitution (up to 3.0 mol%) of ions Pb2+ at Rb+ at T<500 K per order of magnitude reduces the conductivity of the samples obtained, while the nature of its temperature dependence is similar to the temperature dependence of the conductivity of the sample β-PbSnF4. By replacing 5 mol. % of ions with Pb2+ on Rb+, the fluoride ion conductivity at T> 450 K is higher than the conductivity of the initial sample Pb0,86Sn1,14F4 and at temperatures below 450 K by an order of magnitude smaller. With further increase in the content of RbF the electrical conductivity of the samples increases throughout the temperature range, reaching the maximum values at x≥0.15 (σ573 = 0.34–0.41 S/cm, Ea = 0.16 eV and σ373 = (5.34–8.16)•10-2 S/cm, Ea = 0.48–0.51 eV, respectively). In the general case, the replacement of a part of the ions of Pb2+ with Rb+ to an increase in the electrical conductivity of the samples throughout the temperature range. The activation energy of conductivity with an increase in the content of RbF in the low-temperature region in the general case increases, and at temperatures above 400 K is inversely proportional decreasing. The nature of the dependence of the activation energy on the concentration of the heterovalent substituent and its value indicate that the conductivity of the samples obtained increases with an increase in the vacancies of fluoride ions in the structure of the solid solutions.

Effects of MeV Si Ions Modification on the Thermoelectric Properties of SiO2/SiO2+Cu Multilayer Thin Films

2010 ◽  
Vol 1267 ◽  
Author(s):  
John Chacha ◽  
S. Budak ◽  
Cydale Smith ◽  
Marcus Pugh ◽  
Kudus Ogbara ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Ion Beam ◽  
Absolute Temperature ◽  
Conductivity Increase ◽  
Before And After ◽  
The Cross ◽  
Thermoelectric Thin Films

AbstractThe performance of the thermoelectric materials and devices is shown by a dimensionless figure of merit, ZT = S2σT/K, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature and K is the thermal conductivity. ZT can be increased by increasing S, increasing σ, or decreasing K. We have prepared 100 alternating multi-nano layer of SiO2/SiO2+Cu superlattice films using the ion beam assisted deposition (IBAD). The 5 MeV Si ions bombardments have been performed at the different fluences using the AAMU Pelletron ion beam accelerator to make quantum clusters in the multi-layer superlattice thin films to decrease the cross plane thermal conductivity increase the cross plane Seebeck coefficient and cross plane electrical conductivity. To characterize the thermoelectric thin films before and after Si ion bombardments we have measured the cross-plane Seebeck coefficient, the cross-plane electrical conductivity, and the cross-plane thermal conductivity for different fluences.

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