The Influence of Mineralogy and Cation Exchange Capacity toward Electrical Resistivity Value

Electrical Resistivity Tomography (ERT) is a method used for subsurface profiling in soil to characterize soil thickness, fracture zones, soil saturation, salinity and groundwater based on the electrical resistivity value (ERV). There are multiple factors that influence the electrical resistivity value, such as the porosity, degree of saturation, mineralogy, density, cation exchange capacity (CEC), and water resistivity. For this study, the effect of CEC towards resistivity value is studied via controlling the mineralogy factor, saturation, porosity and water resistivity. Thus, via understanding the CEC factor able to relate the resistivity and mineralogy of soil. This study is using a few common minerals in soil and rock, such as kaolinite, montmorillonite, illite, quartz, mica, and feldspar. The particle sizes of all tested minerals were passing 0.063mm sieve. The basic index properties of minerals such as particle size distribution, specific gravity, and Atterberg limit were tested. The instruments of Terrameter LS2 and resistivity box were used to determine the resistivity value of minerals. The Atomic Absorption Spectroscopy (AAS) machine was used to analyze the CEC of minerals via dilute with the ammonium acetate solution. The porosity and degree of saturation of minerals mixed with distill water were controlled between the range of 0.5 to 0.6 and 20% to 100%. The CEC of each mineral has different value, where the lowest and the highest minerals CEC in this study were Kaolinite and Montmorillonite at 1 and 70, respectively. The electrical resistivity values decrease with the increasing of CEC value and degree of saturation. The mineral that has higher CEC indicates lower resistivity value. Meanwhile, via increasing the degree of saturation of minerals were decrease its resistivity values.

Low Sintering Temperature Nano-Silver Pastes with High Bonding Strength by Adding Silver 2-Ethylhexanoate

A silver precursor (silver 2-ethylhexanoate) and silver nanoparticles were synthesized and used to prepare a low sintering temperature nano-silver paste (PM03). We optimized the amount of silver 2-ethylhexanoate added and the sintering temperature to obtain the best performance of the nano-silver paste. The relationship between the microstructures and properties of the paste was studied. The addition of silver 2-ethylhexanoate resulted in less porosity, leading to lower resistivity and higher shear strength. Thermal compression of the paste PM03 at 250 °C with 10 MPa pressure for 30 min was found to be the proper condition for copper-to-copper bonding. The resistivity was (3.50 ± 0.02) × 10−7 Ω∙m, and the shear strength was 57.48 MPa.

Growth and Characterisation of Layered (BA)2CsAgBiBr7 Double Perovskite Single Crystals for Application in Radiation Sensing

A recent publication on single crystals of two-dimensional, layered organic–inorganic (BA)2CsAgBiBr7 double perovskite (BA+ = ) suggested the great potential of this semiconductor material in the detection of X-ray radiation. Our powder XRD measurement confirms the crystallinity and purity of all samples that crystallise in the monoclinic space group , while the single crystal XRD measurements reveal the dominant {001} lattice planes. The structure–property relationship is reflected in the lower resistivity values determined from the van der Pauw measurements (1.65–9.16 × 1010 Ωcm) compared to those determined from the IV measurements (4.19 × 1011–2.67 × 1012 Ωcm). The density of trap states and charge-carrier mobilities, which are determined from the IV measurements, are 1.12–1.76 × 1011 cm–3 and 10−5–10−4 cm2V–1s–1, respectively. The X-ray photoresponse measurements indicate that the (BA)2CsAgBiBr7 samples synthesised in this study satisfy the requirements for radiation sensors. Further advances in crystal growth are required to reduce the density of defects and improve the performance of single crystals.

Optical and electrical properties of Ti-doped In2O3 film deposited on flexible transparent substrates by ion beam assisted deposition under different oxygen flow rate

A flexible transparent is an important technology to improve flexible electronic and flexible display devices. Actually, the deposition process of films coated on a flexible substrate will no more than 200 °C or room temperature. In order to achieve high transmission and lower resistivity, this paper reported the thin films of ITiO deposited by ion beam-assisted electron beam under the condition of different oxygen flow rates at room temperature. The electrical, optical, and morphological properties of ITiO films were investigated under the condition of different oxygen flow rates. At the 30 sccm oxygen flow rate, the surface roughness was 5.4 nm, high transmittance and optical bandgap of ITiO films were 89.2% at 470 nm wavelengths and 3.28 eV, respectively. The lowest resistivity of film was 2.1 × 10-4 Ω-cm at 30 sccm oxygen flow rate. Furthermore, the carrier concentration and hall mobility were experimentally investigated, which presented by 42.8 cm2/Vsec and 9.23 × 1020 cm-3. The use ITiO film coated on a flexible substrate with ion beam-assisted electron beam evaporation at room temperature can improve the lower resistivity and high transmission of the flexible device. It was also demonstrated that ITiO film with ion beam-assisted deposition technique is suitable for flexible electronic and flexible display devices.

Preparation and Properties of Ag-Based Electrical Contact Material Reinforced by Ti3AlC2 Ceramic and its Derivative Ti3C2Tx

As a new kind of two-dimensional carbide material, Ti3C2Tx has revealed its exceptional potentials in many applications. Herein, we successfully prepared the Ag/Ti3C2Tx composite by powder metallurgy and investigated its comprehensive properties by compared with Ag/Ti3AlC2 composite. The Ag/Ti3C2Tx was found to possess the 29% lower resistivity(30×10-3 μΩ·m) than Ag/Ti3AlC2(42×10-3 μΩ·m) and excellent machinability with intermediate hardness (64 HV), showing broad application prospect as non-toxic electrical contact materials. The improved conductivity of Ag/Ti3C2Tx composite is attributed to the metallicity of Ti3C2Tx itself, the good interface bonding between the Ti3C2Tx and Ag, and the microstructural features rendered by the deformability of Ti3C2Tx. Although the arc erosion resistance of Ag/Ti3C2Tx needs to be further improved, it is a powerful and potential alternative material for the Ag/CdO in the further.

Tuning the Electrical Properties of NiO Thin Films by Stoichiometry and Microstructure

Here, the electrical properties of NiO thin films grown on glass and Al2O3 (0001) substrates have been investigated. It was found that the resistivity of NiO thin films strongly depends on oxygen stoichiometry. Nearly perfect stoichiometry yields extremely high resistivity. In contrast, off-stoichiometric thin films possess much lower resistivity, especially for oxygen-rich composition. A side-by-side comparison of energy loss near the edge structure spectra of Ni L3 edges between our NiO thin films and other theoretical spectra rules out the existence of Ni3+ in NiO thin films, which contradicts the traditional hypothesis. In addition, epitaxial NiO thin films grown on Al2O3 (0001) single crystal substrates exhibit much higher resistivity than those on glass substrates, even if they are deposited simultaneously. This feature indicates the microstructure dependence of electrical properties.

Analysis of the performance of grounding grids buried in heterogeneous soil under impulse current

The present paper is devoted to analyzing the transient behaviour of simple grounding grids subjected to impulse lightning current. The transmission line method (TLM) involving mutual coupling between conductors will be used. The transient behaviour of grounding grids buried in homogeneous and in heterogeneous soil is going to be evaluated into a complete time domain solution. Different simulations carried out altering, the influence of the grid dimensions, the kind of the ground and the current injection point on the grid voltage and impedance will be presented. Simulation results will be shown for two extreme cases: in the first case the current is in the center of the grid and in the second one it is injected in one corner of the two configurations of grids. The obtained results show that the grid 1x1 gives the lowest transient potential when the injection point is in lower resistivity side, and the grid 2x2 presents better behavior when the current is injected at center point. It is obvious that the suggested simulations are in a good agreement, with corresponding results of other researchers.

Contribution of ERT on the Study of Ag-Pb-Zn, Fluorite, and Barite Deposits in Northeast Mexico

The results on the effectiveness of five 2D electrical resistivity tomography (ERT) survey profiles for Ag-Pb-Zn, fluorite, and barite exploration Mississippi Valley Type (MVT) and on the magmatic deposits of northeast Mexico, are presented. The profiles were made in areas with mining activities or mineralization outcrops. Schlumberger, dipole-dipole, and Wenner array configurations were used on the measurements. The results showed that electric resistivity can be used to distinguish between mineralized zones. In magmatic-type Pb-Zn and MVT Pb-Zn deposits, resistivity values are shown as low. In magmatic-type fluorite and MVT fluorite deposits, as well as the MVT barite deposit, low-resistivity values are related to Fe sulfides and clays. With these results it is possible to connect observed surface mineralization with underground mineralization. New mineralized zones are also found and their geometries, extensions, and dipping are reported. Therefore, lower resistivity values can be linked to mineral bodies with higher Ag-Pb-Zn contents, as well as bodies enriched in Fe sulfides, Fe oxides, and clays in the fluorite and barite mineralizations. In most ERT models, fractures and faults are identified, indicating a structural control on mineralization. From the geoelectric patterns we can infer the magmatic and MVT origin of these mineral deposits.

Tribological behavior and wear mechanism of Cu/CF/phenolic resin sandwich composites under current

The catenary system was an important part of electrified railway, which provided traction power for electric trains. Cu/CF/phenolic resin contact strip (CFRCS) had been designed with excellent mechanical strength and electrical conductivity. The properties of CFRCS and the pure carbon contact strip (PCCS) were also compared. It could be found that CFRCS not only had higher impact strength than PCCS, but also had lower resistivity, which was favorable for current transmission. This paper analyzed the wear behavior of contact strips from two aspects of wear data and abrasive dust, which was mainly determined by the current and its components. The current-carrying wear mechanism of CFRCS was mainly arc erosion wear, oxidation wear and adhesive wear, while that of PCCS was oxidation wear and arc erosion wear.

Preparation of Aniline-Based Nitrogen-Containing Diamond-Like Carbon Films with Low Electrical Resistivity

The intrinsic high electrical resistivity of diamond-like carbon (DLC) films prevents their use in certain applications. The addition of metal or nitrogen during the preparation of the DLC films leads to a lower resistivity of the films, but it is usually accompanied by several disadvantages, such as a potential contamination risk for surfaces in contact with the film, a limited area that can be coated, deteriorated mechanical properties or low deposition rates of the films. To avoid these problems, DLC films have been prepared by plasma source ion implantation using aniline as a precursor gas, either in pure form or mixed with acetylene. The nitrogen from the precursor aniline is incorporated into the DLC films, leading to a reduced electrical resistivity. Film properties such as hardness, surface roughness and friction coefficient are nearly unchanged as compared to an additionally prepared reference sample, which was deposited using only pure acetylene as precursor gas.