THE ELECTRICAL CONDUCTIVITY OF MOLTEN OXIDES

1953 ◽  
Vol 31 (11) ◽  
pp. 1009-1019 ◽  
Author(s):  
A. E. Van Arkel ◽  
E. A. Flood ◽  
Norman F. H. Bright
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Absolute Temperature ◽  
Molten State ◽  
Melting Points ◽  
Electrical Conductivities ◽  
The Absolute ◽  
Pattern Of Variation ◽  
Molten Oxides

Electrical conductivities of some molten oxides have been determined. In order of decreasing equivalent conductances at their melting points the oxides investigated were: Li2O, PbO, TeO2, MoO3, Bi2O3, V2O5, Sb2O3, and CrO3. The variation of the observed values of the specific conductivities, K, with the absolute temperature, T, can be described by an equation of the form,[Formula: see text]where A, B, C, etc. are constants. While the experimental data are adequately described by an equation of this form containing only the constants A and B, a slightly better fit is obtained using three constants. The conductivities of the molten oxides follow a pattern of variation from element to element which is substantially the same as that of the molten halides. For elements giving more than one oxide stable in the molten state, the oxide corresponding to the highest state of valency has the lowest conductivity.

Partial Carbonization of Aromatic Polyimide Films

1999 ◽  
Vol 593 ◽  
Author(s):  
M. Doyama ◽  
A. Ichida ◽  
Y. Inoue ◽  
Y. Kogure ◽  
T. Nozaki ◽  
...  
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Hall Coefficient ◽  
Carrier Density ◽  
Carrier Mobility ◽  
Absolute Temperature ◽  
Polyimide Films ◽  
Aromatic Polyimide ◽  
The Absolute

ABSTRACTAromatic polyimide films are partially carbonized between 700°C and 1000°C. Electrical conductivity and Hall coeficient have been measured. Electrical conductivity is higher at higher measuring temperatures. The electrical conductivity σ can be expressed as σ= σ0exp (–E /kT), where k is the Boltzman constant. T is the absolute temperature. E depends upon the carborized temperature. The experimental data show the Hall coefficient RH is negative, and this implies the carriers are negatively charged, i.e. electrons. The specimens are n-type semiconductors. The carrier density η can be expressed by η= A1 exp (–E1/κT) and carrier mobility μ can be expressed by μ = A1exp ( E2/κT). E, E1andE2 depend upon the carbonized temperature

Numerical Analysis to Lead Free Solder/Intermetallic Interconnect With Application of Wiedemann-Franz-Lorenz Relation

2012 ◽  
Author(s):  
Yao Yao ◽  
Jared Fry ◽  
Morris Fine ◽  
Leon Keer
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Material Properties ◽  
Interfacial Crack ◽  
Electrical Current ◽  
Lead Free ◽  
Lead Free Solder ◽  
Electrical Conductivities ◽  
Free Solder

Due to the limitation of available experimental data for thermal conductivity of lead free solder and Intermetallic Compound (IMC) materials, the Wiedemann-Franz-Lorenz (WFL) relation is presented in this paper as a possible solution to predict thermal conductivity with known electrical conductivity. The method is based upon the fact that heat and electrical transport both involve the free electrons. The thermal and electrical conductivities of Cu, Ni, Sn, and different Sn rich lead free solder and IMC materials are studied by employing the WFL relation. Generally, the analysis to the experimental data shows that the WFL relation is obeyed in both solder alloy and IMC materials especially matches close to the relation for Sn, with a positive deviation from the theoretical Lorenz number. Thus, with the available electrical conductivity data, the thermal conductivity of solder and IMC materials can be obtained based on the proper WFL relation, vice versa. With the reduction of size of electronic devices and solder interconnects, it has been observed experimentally that solders fail by crack nucleation and propagation near the interface of IMC and bulk solder. A coupled thermal-electrical finite element analysis is performed to study the behavior of lead free solder/IMC interconnects under different electrical current densities. The joule heating, temperature concentration and electrical current concentration effects with a crack propagating near the interface of solder and IMC are investigated numerically. Solder and IMC material properties predicted using the WFL relation are adopted in the computational model. The effects of different thermal and electrical conductivities of solder and IMC materials on interfacial crack tip temperature are analyzed in the present study. By applying the WFL relation, the amount of experiments required to determine the material properties for different lead free solder/IMC interconnects can be significantly reduced, which can lead to pronounced saving of time and cost.

scholarly journals The thermal and electrical conductivities of some pure metals

1925 ◽  
Vol 107 (742) ◽  
pp. 206-227 ◽  
Keyword(s):  
Absolute Temperature ◽  
Independent Method ◽  
Electron Theory ◽  
Slight Tendency ◽  
Electrical Conductivities ◽  
Long Time ◽  
Series Of Experiments ◽  
Pure Metals ◽  
The Absolute ◽  
Experimental Values

The relation between the thermal and electrical conductivities of me has for a long time engaged the attention of physicists. As far back as 1 Wiedemann and Franz propounded the law to the effect that the ratio of two conductivities was the same for all metals. In 1872 Lorenz, both on retical and experimental grounds, sought to establish that the above-mentio ratio was proportional to the absolute temperature. On the development the electron theory Drude, H. A. Lorentz, J. J. Thomson and others ha on the basis of various assumptions, arrived at the same conclusion as Lon Up to 1900, however, the experimental values were too uncertain to allow definite confirmation of the theory. In that year Jaeger and Diesselho published the result of their investigation, which gave directly the ratio of conductivities for a number of metals and alloys over the range 18° to 100° Lees has since, by an independent method, confirmed the values of Jaeger Diesselhorst for a number of metals at 18° C. and has carried the investigat own to —170° C. Meissner has experimented with some pure metals down —250° C. and Onnes and Holst even lower. The result of these investigations has been to show that between —100° C. + 100° C. the value of the function K/ λ T (K and λ being the thermal and ectrical conductivities and T the absolute temperature), is sensibly the samer the pure metals, with perhaps a slight tendency to fall with decreasing temrature. Below —100° C., however, the function shows an increasingly rapid with temperature and a considerable divergence between individual metals, ove a temperature of + 100° C. very few determinations of thermal conictivity have been made, and the object of the present series of experiments is been to measure, in this region, the thermal and electrical conductivities a number of metals of the highest purity obtainable commercially.

Vapour pressure and ideality of the equimolar mixture of H2O and D2O

1980 ◽  
Vol 33 (11) ◽  
pp. 2357 ◽  
Author(s):  
G Jancso ◽  
G Jakli
Keyword(s):  
Experimental Data ◽  
Isotope Effect ◽  
Vapour Pressure ◽  
Liquid Mixture ◽  
Geometric Mean ◽  
Absolute Temperature ◽  
Equimolar Mixture ◽  
The Absolute ◽  
The Law ◽  
The Ideal

The pressure differences between H2O and the equimolar H2O-D2O mixture were measured between 5 and 90°C and the experimental data can be represented by the equation ����������������� In(pH2O/pmix) = 0.076624-88.161/T+25972/T2 where T is the absolute temperature. For comparison the vapour-pressure differences between pure H2O and D2O were also determined. The results show that the H2O-HDO-D2O liquid mixture does not deviate from the ideal behaviour within the limits of the experimental data. The present investigation supports the earlier conclusion that the law of the geometric mean for the vapour-pressure isotope effect in the series H2O, HDO and D2O is not obeyed.

Electrical conductivity studies on silica phases and the effects of phase transformation

2019 ◽  
Vol 104 (12) ◽  
pp. 1800-1805
Author(s):  
George M. Amulele ◽  
Anthony W. Lanati ◽  
Simon M. Clark
Keyword(s):  
Electrical Conductivity ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Hydrogen Charge ◽  
Charge Compensation ◽  
Composition Analysis ◽  
Conductivity Measurements ◽  
Pressure System ◽  
Electrical Conductivities ◽  
Silica Phases

Abstract Starting with the same sample, the electrical conductivities of quartz and coesite have been measured at pressures of 1, 6, and 8.7 GPa, respectively, over a temperature range of 373–1273 K in a multi-anvil high-pressure system. Results indicate that the electrical conductivity in quartz increases with pressure as well as when the phase change from quartz to coesite occurs, while the activation enthalpy decreases with increasing pressure. Activation enthalpies of 0.89, 0.56, and 0.46 eV, were determined at 1, 6, and 8.7 GPa, respectively, giving an activation volume of –0.052 ± 0.006 cm3/mol. FTIR and composition analysis indicate that the electrical conductivities in silica polymorphs is controlled by substitution of silicon by aluminum with hydrogen charge compensation. Comparing with electrical conductivity measurements in stishovite, reported by Yoshino et al. (2014), our results fall within the aluminum and water content extremes measured in stishovite at 12 GPa. The resulting electrical conductivity model is mapped over the magnetotelluric profile obtained through the tectonically stable Northern Australian Craton. Given their relative abundances, these results imply potentially high electrical conductivities in the crust and mantle from contributions of silica polymorphs. The main results of this paper are as follows:The electrical conductivity of silica polymorphs is determined by impedance spectroscopy up to 8.7 GPa.The activation enthalpy decreases with increasing pressure indicating a negative activation volume across the silica polymorphs.The electrical conductivity results are consistent with measurements observed in stishovite at 12 GPa.

Dual percolations of electrical conductivity and electromagnetic interference shielding in progressively agglomerated CNT/polymer nanocomposites

2021 ◽  
pp. 108128652110214
Author(s):  
Xiaodong Xia ◽  
George J. Weng
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Nanocomposites ◽  
Electromagnetic Interference ◽  
Effective Medium Theory ◽  
Scale Model ◽  
Shielding Effectiveness ◽  
Emi Shielding

Recent experiments have revealed two distinct percolation phenomena in carbon nanotube (CNT)/polymer nanocomposites: one is associated with the electrical conductivity and the other is with the electromagnetic interference (EMI) shielding. At present, however, no theories seem to exist that can simultaneously predict their percolation thresholds and the associated conductivity and EMI curves. In this work, we present an effective-medium theory with electrical and magnetic interface effects to calculate the overall conductivity of a generally agglomerated nanocomposite and invoke a solution to Maxwell’s equations to calculate the EMI shielding effectiveness. In this process, two complex quantities, the complex electrical conductivity and complex magnetic permeability, are adopted as the homogenization parameters, and a two-scale model with CNT-rich and CNT-poor regions is utilized to depict the progressive formation of CNT agglomeration. We demonstrated that there is indeed a clear existence of two separate percolative behaviors and showed that, consistent with the experimental data of poly-L-lactic acid (PLLA)/multi-walled carbon nanotube (MWCNT) nanocomposites, the electrical percolation threshold is lower than the EMI shielding percolation threshold. The predicted conductivity and EMI shielding curves are also in close agreement with experimental data. We further disclosed that the percolative behavior of EMI shielding in the overall CNT/polymer nanocomposite can be illustrated by the establishment of connective filler networks in the CNT-poor region. It is believed that the present research can provide directions for the design of CNT/polymer nanocomposites in the EMI shielding components.

The specific heats of three paramagnetic salts at very low temperatures

1956 ◽  
Vol 237 (1210) ◽  
pp. 395-403 ◽  
Keyword(s):  
Specific Heat ◽  
Absolute Temperature ◽  
Magnesium Nitrate ◽  
Paramagnetic Resonance ◽  
Specific Heats ◽  
Ammonium Alum ◽  
Relaxation Measurements ◽  
Ferric Ammonium ◽  
The Absolute ◽  
Measured Specific Heat

The specific heats of three paramagnetic salts, neodymium magnesium nitrate, manganous ammonium sulphate and ferric ammonium alum, have been measured at temperatures below 1°K using the method of γ -ray heating. The temperature measurements were made in the first instance in terms of the magnetic susceptibilities of the salts, the relation of the susceptibility to the absolute temperature having been determined for each salt in earlier experiments. The γ -ray heatings gave the specific heat in arbitrary units. The absolute values of the specific heats were found by extrapolating the results of paramagnetic relaxation measurements at higher temperatures. The measured specific heat of neodymium magnesium nitrate is compared with the value calculated from paramagnetic resonance data, and good agreement is found.

A Fluidity-Temperature Relationship for Liquids

1973 ◽  
Vol 95 (2) ◽  
pp. 236-241
Author(s):  
T. F. Ford ◽  
C. R. Singleterry
Keyword(s):  
Interpolation Formula ◽  
Absolute Temperature ◽  
Temperature Relationship ◽  
Organic Liquids ◽  
Low Viscosity ◽  
Linear Relationships ◽  
Temperature Ranges ◽  
The Absolute ◽  
The Relationship

Many relationships between viscosity or its reciprocal, fluidity, and temperature have been proposed for liquids. None except the empirically modified ASTM chart have proven satisfactory over extended temperature ranges. We here note that by plotting the kinematic fluidity (φkin) against the square of the absolute temperature (deg K2) we obtain linear relationships for a wide variety of organic liquids at kinematic viscosities less than about 1.67 centistokes (or fluidities above about 0.60 reciprocal centistokes). The generality of the relationship appears to justify the use of the equation, φkin=a+bT2, as an interpolation formula for organic liquids in the low viscosity region.

Measuring transient solute transport through the vadoze zone using time domain reflectometry

Soil Research ◽  
2001 ◽  
Vol 39 (6) ◽  
pp. 1359 ◽  
Author(s):  
I. Vogeler ◽  
S. Green ◽  
A. Nadler ◽  
C. Duwig
Keyword(s):  
Electrical Conductivity ◽  
Solute Transport ◽  
Time Domain ◽  
Deterministic Model ◽  
Soil Surface ◽  
Time Domain Reflectometry ◽  
Richards Equation ◽  
Electrical Conductivities ◽  
Destructive Measurement

Time domain reflectometry (TDR) was used to monitor the transport of conservative tracers in the field under transient water flow in a controlled experiment under a kiwifruit vine. A mixed pulse of chloride and bromide was applied to the soil surface of a 16 m2 plot that had been isolated from the surrounding orchard soil. The movement of this solute pulse was monitored by TDR. A total of 63 TDR probes were installed into the plot for daily measurements of both the volumetric water content (θ) and the bulk soil electrical conductivity (σa). These TDR-measured σa were converted into pore water electrical conductivities (σw) and solute concentrations using various θ–σa–σw relationships that were established in the laboratory on repacked soil. The depth-wise field TDR measurements were compared with destructive measurement of the solute concentrations at the end of the experiment. These results were also compared with predictions using a deterministic model of water and solute transport based on Richards’ equation, and the convection–dispersion equation. TDR was found to give a good indication of the shape of the solute profile with depth, but the concentration of solute was under- or over-estimated by up to 50%, depending on the θ–σa–σw relationships used. Thus TDR can be used to monitor in situ transport of contaminants. However, only rough estimates of the electrical conductivity of the soil solution can so far be obtained by TDR.

scholarly journals Absolute temperature directly from plank’s profile: A simulation

2021 ◽  
Vol 33 (2) ◽  
pp. 9-19
Author(s):  
V. VIJAYAKUMAR ◽  
Keyword(s):  
Thermal Radiation ◽  
Response Function ◽  
Wave Length ◽  
Absolute Temperature ◽  
Scale Factor ◽  
Material Surface ◽  
Measured Spectrum ◽  
The Absolute

The measured thermal radiation from a material surface will, in general, have a wave length (\lambda) dependent scale-factor to the Planck profile (PT) from the contributions of the emissivity (Є\lambda) of the surface, the response function (A\lambda) of the measurement setup, and the emission via non-Plank processes. For obtaining the absolute temperature from such a profile, a procedure that take care of these dependencies and which relay on a temperature grid searchis proposed. In the procedure, the deviation between the Plank profiles at various temperatures and the measured spectrum that is made equal to it at a selected wavelength, by scaling, is used. The response function (A\lambda) is eliminated at the measurement stage and the polynomial dependence of the remnant scale factor mostly dominated by Є\lambda) i s extracted from the measured spectrum by identifying its optimal \lambda dependence. It is shown that when such a computation is carried out over a temperature grid, the absolute temperature can be identified from the minimum of the above deviation. Here, search for T and Є\lambda) d elinked, unlike in the leastsquare approaches that are normally employed. Code that implements the procedure is tested with simulated Planck profile to which different viable values of Є\lambda) a nd noise is incorporated. It shown that if the \lambda dependence of scale-factor is not too high, the absolute temperature can be recovered. A large \lambda dependent scale-factor and the consequent possible error in the temperature obtained can also be identified.

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