Journal articles: 'Electromotive composition'

1

HIRATA, Yoshihiro, and Manabu MATSUDA. "Composition Dependence of Electromotive Force of Silica-Alumina Ceramics as Oxygen Solid Electrolyte." Journal of the Ceramic Society of Japan 102, no. 1183 (1994): 241–46. http://dx.doi.org/10.2109/jcersj.102.241.

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Kopyto, M., G. Garzel, and L. A. Zabdyr. "Thermodynamic properties of the liquid Bi-Cu-Sn lead-free solder alloys." Journal of Mining and Metallurgy, Section B: Metallurgy 45, no. 1 (2009): 95–100. http://dx.doi.org/10.2298/jmmb0901095k.

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The electromotive force measurement method was employed to determine the thermodynamic properties of liquid Bi-Cu-Sn alloys using solid electrolyte galvanic cells as shown below: Kanthal+Re, Bi-Cu-Sn, SnO2 | Yttria Stabilized Zirconia | air, Pt, Po2=0.2:1 atm Measurements were carried out for three cross-sections with constant Bi/Cu ratio equal to: 1/3, 1 and 3 and for various tin content varying every 10%, resulting in a total of 26 different alloy compositions. The temperature of the measurements varied within the range from 973 to 1325 K. A linear dependence of the e.m.f. on temperature was observed for all alloy compositions and the appropriate line equations were derived. Tin activities were calculated as function of composition and temperature. Results were presented in tables and figures.

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Ahmed, Soleen S., and Lazgin A. Jamil. "Determination of Dissociation Constants of Malonic Acid in (Ethylene Glycol-Water)X% Mixed Solvent at Different Temperatures Using Electromotive Force Measurements." Science Journal of University of Zakho 7, no. 1 (March 30, 2019): 18–26. http://dx.doi.org/10.25271/sjuoz.2019.7.1.573.

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The first and second dissociation constants of malonic acid in different composition of (ethylene glycol-water)%, (10, 20 and 30)% mixed solvent determined using the electromotive force measurements of galvanic cells without liquid junction at nine different temperatures, at interval, including the body temperature. The value of the first and second thermodynamic dissociation constants have been used to determine the thermodynamic quantities of two dissociation processes. These quantities involved the standard free energy, standard enthalpy change, standard entropy change, and standard heat capacity change.

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Mukhopadhyay, Sukanya, and K. T. Jacob. "Theoretical Analysis of the Electromotive Force of a Cell Incorporating a Composition Gradient Solid Electrolyte." Journal of The Electrochemical Society 142, no. 1 (January 1, 1995): 161–65. http://dx.doi.org/10.1149/1.2043857.

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Levkov, Leonid, Denis Pankratov, and Dmitry Shurygin. "Iron Oxidation State Analysis in ESR Slag." Materials Science Forum 946 (February 2019): 437–43. http://dx.doi.org/10.4028/www.scientific.net/msf.946.437.

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It is shown that the value of the equilibrium oxygen partial pressure,Po2as a value available for measurements is possible to be taken as a measure of slag redox potential of, taking into account its electronic system performance. Application of the electromotive force method (EMF) allowed establishing the character of a change in the average oxidation state of iron νFedepending onPo2, the temperature and slag composition. The study of Mössbauer absorption spectra of quenched slag samples confirmed the possibility of simultaneous presence of iron in the flux in oxidation states from 0 to +3.

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Katayama, Iwao, Keiko Shimazawa, Dragana Živković, Dragan Manasijević, Živan Živković, and Takamichi Iida. "Activity measurements of Ga in liquid Ga–Tl alloys by EMF method with zirconia solid electrolyte." International Journal of Materials Research 94, no. 12 (December 1, 2003): 1296–99. http://dx.doi.org/10.1515/ijmr-2003-0234.

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Abstract Electromotive force measurements (EMF) of an electrochemical cell with zirconia as solid electrolyte were performed to determine the Ga activity from 973 to 1273 K in the entire composition range of liquid Ga–Tl alloys. In the whole concentration range, the activity of Ga shows large positive deviations from ideality, and the activity of Tl which is derived by the Gibbs–Duhem equation shows also positive deviation from ideality. The parameters of the Redlich – Kister equation for excess Gibbs energies of mixing are determined from the results obtained in this study which were compared with Chou’s model calculation.

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Kurapova, O. Yu, M. M. Pivovarov, K. V. Nikiforova, and V. G. Konakov. "Sensor Properties of Stabilized Zirconia Ceramics, Manufactured from Nanopowders." REVIEWS ON ADVANCED MATERIALS SCIENCE 57, no. 2 (July 1, 2018): 257–61. http://dx.doi.org/10.1515/rams-2018-0071.

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Abstract The paper reports the data on the sensing properties of xCaO-(100-x)ZrO2 (CSZ, x=9, 12 and 15 mol.%) and 8Y2O3-92ZrO2 (YSZ) solid electrolytes, manufactured from nanosized lowagglomerated powder. Stabilized zirconia solid electrolytes (SE) were synthesized via the original co-precipitation technique and annealing at 1823K in air for 3 hours. Phase composition and conductivity of obtained ceramics was investigated via XRD and impedance spectroscopy techniques. Electromotive force (EMF) response on O2 partial pressure was obtained at 966K for sensors with stabilized zirconia membranes. The data obtained was compared with Nernst equation. The impact of the precursor powder synthesis technique on electrical and sensing properties was discussed.

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Garzel, G., M. Kopyto, and L. A. Zabdyr. "Thermodynamic properties of the liquid Ag-Bi-Cu-Sn lead-free solder alloys." Journal of Mining and Metallurgy, Section B: Metallurgy 50, no. 2 (2014): 145–48. http://dx.doi.org/10.2298/jmmb130727015g.

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The electromotive force measurement method was employed to determine the thermodynamic properties of liquid Ag-Bi-Cu-Sn alloys using solid electrolyte galvanic cells as shown below: Kanthal+Re, Ag-Bi-Cu-Sn, SnO2 | Yttria Stabilized Zirconia | air, Pt, Experiments were made within temperature interval: 950 - 1300K along four composition paths of constant ratios: XAg : XBi : XCu = 1, XAg : (XBi + XCu) = 3:2 for XBi = XCu, XBi : (XAg + XCu) = 3:2 for XAg = XCu and XCu : (XAg + XBi) = 3:2 for XAg = XBi and tin concentration changing from 0.1 to 0.9 mole fractions, every 0.1. Almost all the results were approximated by straight line equations: EMF vs T, and tin activities were then calculated in arbitrary temperature; measurement results were presented by graphs. Unusual activity plot for XBi : (XAg + XCu) = 3:2 composition path was most probably caused by miscibility gap detected earlier in Bi-Cu-Sn ternary liquid alloys.

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Jacob, K. Thomas, Niladri Dasgupta, Helfried Näfe, and Fritz Aldinger. "Measurement of Gibbs energy of formation of LaGaO3 using a composition-graded solid electrolyte." Journal of Materials Research 15, no. 12 (December 2000): 2836–43. http://dx.doi.org/10.1557/jmr.2000.0405.

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A composition-graded solid electrolyte (LaF3)y · (CaF2)1-y was used for the measurement of the standard Gibbs energy of formation of LaGaO3 from its component oxides. An equimolar mixture of CaO and CaF2 was employed as the reference electrode. The composition of the working electrode depended on temperature. A three-phase mixture of LaGaO3 + Ga2O3 + LaF3 was used in the temperature range from 910 to 1010 K, while a mixture of LaGaO3 + Ga2O3 + LaO1-xF1+2x was employed from 1010 to 1170 K. Both the reference and working electrodes were placed under pure oxygen gas. Because of the high activity of LaF3 at the working electrode, there was significant diffusion of LaF3 into CaF2. The composition-graded electrolyte was designed to minimize the electrode–electrolyte interaction. The concentration of LaF3 varied across the solid electrolyte; from y = 0 near the reference electrode to a maximum value y = 0.32 at the working electrode. For the correct interpretation of the electromotive force at T > 1010 K, it was necessary to use thermodynamic properties of the lanthanum oxyfluoride solid solution. The standard Gibbs energy of formation of LaGaO3 from its component oxides according to the reaction, ½La2O3 (A-rare earth) + ½Ga2O3 (b) → LaGaO3 (rhombohedral) can be represented by the equation: δGo f,(ox) /J mol -1 = –46 230 + 7.75 T/K (±1500).

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Moroz, Mykola, Fiseha Tesfaye, Pavlo Demchenko, Myroslava Prokhorenko, Nataliya Yarema, Daniel Lindberg, Oleksandr Reshetnyak, and Leena Hupa. "The Equilibrium Phase Formation and Thermodynamic Properties of Functional Tellurides in the Ag–Fe–Ge–Te System." Energies 14, no. 5 (February 28, 2021): 1314. http://dx.doi.org/10.3390/en14051314.

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Equilibrium phase formations below 600 K in the parts Ag2Te–FeTe2–F1.12Te–Ag2Te and Ag8GeTe6–GeTe–FeTe2–AgFeTe2–Ag8GeTe6 of the Fe–Ag–Ge–Te system were established by the electromotive force (EMF) method. The positions of 3- and 4-phase regions relative to the composition of silver were applied to express the potential reactions involving the AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 compounds. The equilibrium synthesis of the set of phases was performed inside positive electrodes (PE) of the electrochemical cells: (−)Graphite ‖LE‖ Fast Ag+ conducting solid-electrolyte ‖R[Ag+]‖PE‖ Graphite(+), where LE is the left (negative) electrode, and R[Ag+] is the buffer region for the diffusion of Ag+ ions into the PE. From the observed results, thermodynamic quantities of AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 were experimentally determined for the first time. The reliability of the division of the Ag2Te–FeTe2–F1.12Te–Ag2Te and Ag8GeTe6–GeTe–FeTe2–AgFeTe2–Ag8GeTe6 phase regions was confirmed by the calculated thermodynamic quantities of AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 in equilibrium with phases in the adjacent phase regions. Particularly, the calculated Gibbs energies of Ag2FeGeTe4 in two different adjacent 4-phase regions are consistent, which also indicates that it has stoichiometric composition.

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Tanasescu, Speranta, Florentina Maxim, Florina Teodorescu, and Liviu Giurgiu. "Influence of Composition and Particle Size on Spin Dynamics and Thermodynamic Properties of Magnetoresistive Perovskites." Journal of Nanoscience and Nanotechnology 8, no. 2 (February 1, 2008): 914–23. http://dx.doi.org/10.1166/jnn.2008.d127.

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The thermodynamic behavior and spin dynamics of the colossal magnetoresistive (CMR) perovskites of general formula La1−x(A)xMn1−y(B)yO3 (where A is an alkaline earth, and B = Al, In) have been studied in order to evidence the effect of composition and the influence of nanocrystallinity on the thermodynamic and magnetic characteristics. By using electron paramagnetic resonance (EPR) spectroscopy, the behavior of the exchange coupling integral (J) between Mn spins and the polaron activation energy (Ea) have been investigated. The thermodynamic properties represented by the relative partial molar free energies, enthalpies and entropies of oxygen dissolution in the perovskite phase, as well as the equilibrium partial pressures of oxygen have been obtained by using solid electrolyte electrochemical cells method. The influence of the oxygen stoichiometry change on the thermodynamic properties was examined using the data obtained by a coulometric titration technique coupled with measurements of the electromotive force (EMF). The results were correlated with the average Mn valence values as determined by redox titration. The properties of the rare-earth manganites are strongly affected by the A- and B-site substitution and by the oxygen nonstoichiometry. New features related to the modifications in properties connected with the nanocrystalline state were evidenced. The correlation existing between the magnetic and thermodynamic characteristics were discussed in relation to significant changes in the overall concentration of defects.

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Berdiyarov, B., Sh Khojiev, O. Nuraliyev, B. Mirsaotov, S. Mirsaotov, and Z. Osmanov. "Monitoring the oxygen removal process at the final stage of melting steel." Journal of Physics: Conference Series 2131, no. 2 (December 1, 2021): 022071. http://dx.doi.org/10.1088/1742-6596/2131/2/022071.

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Abstract This article deals with removing oxygen at the final stage of steel smelting in arc steel-making furnaces. It is shown that the remaining oxygen during crystallization forms floccules and significantly reduces the quality of the finished metal. During the subsequent metal processing by pressure on these floccules, the metal is torn apart and makes it impossible to obtain a steel sheet. Deoxidation is performed with expensive ferroalloys, and their consumption must be minimized. To achieve economic efficiency, it has been proposed to use recycled aluminum slag as a relatively inexpensive local deoxidizer. To optimize the deoxidizer consumption, a rapid analysis method was developed using the electromotive force (EMF) determination to determine the oxygen activity in liquid steel. As a result of the study, the composition, structure, and technological parameters of deoxidized steel were determined. The use of this technology in production will make it possible to obtain high-quality steel and improve environmental protection through secondary aluminum waste.

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Demarest, J. R., and A. L. Finn. "Characterization of the basolateral membrane conductance of Necturus urinary bladder." Journal of General Physiology 89, no. 4 (April 1, 1987): 541–62. http://dx.doi.org/10.1085/jgp.89.4.541.

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Necturus urinary bladders stripped of serosal muscle and connective tissue were impaled through their basolateral membranes with microelectrodes in experiments that permitted rapid changes in the ion composition of the serosal solution. The transepithelial electrical properties exhibited a marked seasonal variation that could be attributed to variations in the conductance of the shunt pathway, apical membrane selectivity, and basolateral Na+ transport. In contrast, the passive electrical properties of the basolateral membrane remained constant throughout the year. The apparent transference numbers (Ti) of the basolateral membrane for K+ and Cl- were determined from the effect on the basolateral membrane equivalent electromotive force of a sudden increase in the serosal K+ concentration from 2.5 to 50 mM/liter or a decrease in the Cl- concentration from 101 to 10 mM/liter. TK and TCl were 0.71 +/- 0.05 and 0.04 +/- 0.01, respectively. The basolateral K+ conductance could be blocked by Ba2+ (0.5 mM), Cs+ (10 mM), or Rb+ (10 mM), but was unaffected by 3,4-diaminopyridine (100 microM), decamethonium (100 microM), or tetraethylammonium (10 mM). We conclude that a highly selective K+ conductance dominates the electrical properties of the basolateral membrane and that this conductance is different from those found in nerve and muscle membranes.

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Mareci, Daniel, Catalin Bocanu, Neculai Aelenei, and Gheorghe Nemtoi. "Galvanic Corrosion Between Ti/Ti6Al4V and Various Dental Alloys." Eurasian Chemico-Technological Journal 6, no. 3 (July 13, 2017): 221. http://dx.doi.org/10.18321/ectj615.

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The corrosion tendencies of metals are related with their position in the electromotive series. These electrode potential degrees may change due to the composition of the alloys, the surrounding medium or due to the alterations in the composition because of the recurrent costing. The galvanic corrosion appears when different electrochemical potentials are bound to one another and the electrical conductibility is assured by the presence of an electrolyte. It is difficult to avoid coupling of different metals, a problem concerning the choice of the alloy used for the implant bone supra-structure. One has studied the galvanism of several couples formed between a dental implant and diverse dental alloys in Afnor saliva. The electrochemical behavior of 8 commercial dental alloy superstructures with titanium and titanium alloy (Ti6Al4V) implants was investigated by electrochemical techniques. Non-precious alloys were Ni-Cr based (Wiron NT and Verasoft), Co-Cr based (Vitallium alloy) and Cu based (Gaudent). Semi-precious alloys were Ag-Pd based (RX91 and Unique White). The precious alloys were Au-Pd based (Ceram) and Au-Ag based (Argenco). Some of the corroded and non-corroded surfaces were observed by optical microscopy. From linear polarization curves the corrosion potential and the current densities were evaluated. The results showed very low corrosion rates, ranking from 10-6 to 10-9 A/cm2. All the results obtained indicate the fact that the corrosion process intensity corresponding to the coupling between titanium (respectively Ti6Al4V) and semi-precious alloys is reduced. The surface of precious and semi-precious alloys is not attacked, but the titanium (Ti6Al4V) surface is oxidized in time.

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Das, Bijan. "Thermodynamics of electrolytes in mixed solvent media Application of the Pitzer ion interaction approach." Canadian Journal of Chemistry 83, no. 12 (December 1, 2005): 2032–38. http://dx.doi.org/10.1139/v05-222.

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Although for a long time considerable attention has been paid to the application of the Pitzer ion interaction approach to describe the thermodynamic properties of a variety of aqueous electrolyte solutions, such studies in mixed solvent media are still scarce. The present paper discusses the application of the Pitzer ion interaction approach in the case of electrolyte solutions in mixed solvent media. In particular, a comprehensive equation for the thermodynamic properties of hydrochloric acid in dioxanewater mixtures within the temperature range 273.15 to 323.15 K has been generated in the ion interaction (Pitzer) equation form on the basis of electrochemical cell measurements of the hydrochloric acid available in the literature. It was necessary to set varying values of the exponential coefficients α1 and α2 of the standard Pitzer model in different mixed solvent media to achieve a satisfactory fit. The present model quantitatively reproduces the experimental cell electromotive forces over the entire concentration and temperature range used for the experiments. The Pitzer ion interaction approach is, thus, proved to be a very valuable method for the correlation and prediction of thermodynamic properties of electrolytes in mixed solvent media. The implications of the Pitzer ion interaction parameters (β(0), β(1) β(2), and Cϕ) have also been discussed in terms of interionic forces. The present study also stresses the need for additional emf measurements to help interpolation through the dioxane composition. Key words: Pitzer's equations, Pitzer ion interaction parameter, activity coefficients, emf, hydrochloric acid.

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Isaacson, L., and S. Nicolson. "CONCEALED TRANSEPITHELIAL POTENTIALS AND CURRENT RECTIFICATION IN TSETSE FLY MALPIGHIAN TUBULES." Journal of Experimental Biology 186, no. 1 (January 1, 1994): 199–213. http://dx.doi.org/10.1242/jeb.186.1.199.

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1. Electrophysiological techniques have been applied to tsetse fly Malpighian tubules for the first time. 2. In either Cl- or SO42- Ringer, both non-perfused and perfused tubules displayed transtubular potentials (Vt) at or close to 0 mV. Exposure to cyclic AMP elicited a marked secretory response and, in SO42- Ringer, a sharp (lumen-positive) increase in Vt. In Cl- Ringer, despite more than double the secretory response, there was little or no change in Vt. 3. Replacing Cl- with SO42- Ringer, in the presence of cyclic AMP, promptly increased Vt. In perfused tubules, this occurred irrespective of the Cl- or SO42- composition of the perfusate. 4. In Cl- Ringer, the transepithelial resistance (Rtrans) was less than half that previously reported in Malpighian tubules of other species. Cyclic AMP reduced Rtrans still further, whether tubules were bathed in Cl- or SO42- Ringer. 5. Currentvoltage (I/V) plots often displayed current rectification, both before and more frequently after exposure to cyclic AMP, thus permitting estimation of both the electromotive force of the Na+ transport mechanism (ENa) and of the shunt resistance (Rshunt). Both ENa and Rshunt were markedly lower in tubules bathed in Cl- than in SO42- Ringer. Cyclic AMP was without effect on ENa and Rshunt, in either Cl- or SO42- Ringer. 6. In terms of the equivalent electrical circuit, the secretory response to cyclic AMP was due solely to a fall in resistance of the active transport pathway (Rseries). The absence of an appreciable Vt, in Cl- Ringer, is consistent with an apical Cl- shunt.

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Molokanov, V. V., A. V. Krutilin, N. A. Palii, T. R. Chueva, and P. P. Umnov. "Determination of temperature regimes for annealing of ferromagnetic amorphous wires obtained by the Ulitovsky – Taylor method during heating by direct current flow." Physics and Chemistry of Materials Treatment 2 (2022): 71–78. http://dx.doi.org/10.30791/0015-3214-2022-2-71-78.

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The direct current (dc) heating effect of ferromagnetic amorphous wires (AW) on the electromagnetic properties of the serial Co-based alloy, Co – Fe – Cr – Si – B, is investigated. The Ulitovsky – Taylor method was used to produce AW with diameters D = 40, 70, 82, 98, 123, and 145 μm in a glass shell, that was removed mechanically by elastic bending on a laboratory bench. The developed in situ method of stepwise cyclic dc heating of AW of various diameters enables to choose the optimal values of the current (Ia) for carrying out the selected modes that maximize the magnetic properties. AW electromagnetic properties were monitored by registering the amplitude of the intrinsic electromagnetic signal of electromotive force (EMF) of the AW sample under study. Since reliable direct measurements of AW temperature (Ta) when passing the current (Ia) quite an undertakings, we used indirect method of AW heating temperature estimation by establishing the relationship Ta = f (Ia). For the AW specified diameters, the direct current values were experimentally determined, which ensure optimal heat treatment in the range of temperature stability of the amorphous phase, up to the crystallization temperature, Tx. A calibration curve was constructed using reference temperature points, i.e. Tx and the Curie temperature (Tc). The proposed technique for calibration graph construction I = f(D) may be used for different AWs that have different diameters and same composition; it allows one to determine the modes of current annealing required for the best EMF amplitude values of amorphous wires of the given diameter, up to 100 μm.

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Sorek, A., and Z. Kudliński. "The Influence of the Near-Meniscus Zone in Continuous Casting Mold on the Surface Quality of the Continuous Casting Ingots." Archives of Metallurgy and Materials 57, no. 1 (March 1, 2012): 371–77. http://dx.doi.org/10.2478/v10172-012-0036-1.

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The Influence of the Near-Meniscus Zone in Continuous Casting Mold on the Surface Quality of the Continuous Casting IngotsThe physical, chemical and mechanical phenomena which take place in the near-meniscus zone of continuous casting mold are the significant factors influencing the quality of CC ingot and especially the quality of its surface. Such phenomena consist of the following processes: lubrication of the ingot surface by the liquid slag-forming phase of mold powder, creation of meniscus, formation of the specific kind of galvanic cell and connected with this cell ions migration of liquid mold powder. Application of the mold powders is the commonly used lubrication method of the surface of CC ingots in mold (in near-meniscus zone). According to the ionic structure theory of the liquid metallurgical slags the following thesis can be formulated: the liquid slag-forming phase of mold powder is the ionic liquid. The ionic liquid occurs between two metals: the copper wall of mold and the steel surface of ingot can create a specific kind of galvanic cell in the upper part of mold (the near-meniscus zone of mold). The paper presents results of industrial research of low-carbon steel continuous casting. The electromotive force of galvanic cell situated in the upper (near-meniscus) part of CC mold was measured. Moreover, the influence of applied powders with different alkalinity on the character of oscillatory marks forming on the ingot surface was considered. The galvanic cell, which is created in the upper part of mold in the near-meniscus zone, can cause the essential change of the chemical composition of electrolyte (liquid phase of mold powder) in the near-electrodes zones. So in the process the condition of lubrication and character of obtained oscillatory mark can also be changed.

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Jacob, K. T., K. T. Lwin, and Yoshio Waseda. "System Pr –Pd–O: Phase Diagram and Thermodynamic Properties of Ternary Oxides Using Solid-State Cells with Special Features." International Journal of Materials Research 92, no. 7 (July 1, 2001): 731–39. http://dx.doi.org/10.1515/ijmr-2001-0138.

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Abstract An isothermal section of the phase diagram for the system Pr– Pd–O at 1223 K has been established by equilibration of samples representing 13 different compositions, and phase identification after quenching by optical and scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive analysis of X-rays (EDX). The binary oxide PdO was not stable at 1223 K. Three oxide phases were stable along the binary Pr– O; Pr2O3, Pr7O12 and a phase of variable composition between these two oxides designated as σ. Two ternary oxides Pr4PdO7 and Pr2Pd2O5 were identified and their crystal structures were determined. Liquid alloy, the intermetallic compounds PrPd, Pr3Pd4, PrPd3, PrPd5, and Pd-rich solid solution (Pds.s.) were found to be in equilibrium with Pr2O3. Based on the phase relations, two solid-state cells were designed to measure the Gibbs energies of formation of the two ternary oxides. An advanced version of the solid-state cell incorporating a buffer electrode was used for high temperature thermodynamic measurements. The function of the buffer electrode, placed between reference and working electrodes, was to absorb the electrochemical flux of the mobile species through the solid electrolyte caused by trace electronic conductivity. The buffer electrode prevented polarization of the measuring electrode and ensured accurate data. Yttria-stabilized zirconia was used as the solid electrolyte and pure oxygen gas at a pressure of 0.1 MPa as the reference electrode. Electromotive force measurements, conducted in the temperature range 925 – 1400 K, indicated the presence of a third ternary oxide Pr2PdO4, stable below 1150 ± 9 K. Additional solid state cells were designed to study this compound. The standard Gibbs energy of formation of the interoxide compounds from their component binary oxides Pr2O3 and PdO can be represented by the following equations: Pr 4 PdO 7 : Δ f ( ox ) G o /J ⋅ mol − 1 = − 43 540 + 0.74 T ( ± 150 ) Pr 2 PdO 4 : Δ f ( ox ) G o /J ⋅ mol − 1 = − 38 805 + 1.91 T ( ± 120 ) Pr 2 Pd 2 O 5 : Δ f ( ox ) G o /J ⋅ mol − 1 = − 68 640 + 1.28 T ( ± 270 ) $$\eqalign{ & {\rm{P}}{{\rm{r}}_4}{\rm{Pd}}{{\rm{O}}_7}:{{\rm{\Delta }}_{{\rm{f}}\left( {{\rm{ox}}} \right)}}{G^{\rm{o}}}{\rm{/J}} \cdot {\rm{mo}}{{\rm{l}}^{ - 1}} = - 43\,540 + 0.74\,T\left( { \pm 150} \right) \cr & {\rm{P}}{{\rm{r}}_2}{\rm{Pd}}{{\rm{O}}_4}:{{\rm{\Delta }}_{{\rm{f}}\left( {{\rm{ox}}} \right)}}{G^{\rm{o}}}{\rm{/J}} \cdot {\rm{mo}}{{\rm{l}}^{ - 1}} = - 38\,805 + 1.91\,T\left( { \pm 120} \right) \cr & {\rm{P}}{{\rm{r}}_2}{\rm{P}}{{\rm{d}}_2}{{\rm{O}}_5}:{{\rm{\Delta }}_{{\rm{f}}\left( {{\rm{ox}}} \right)}}{G^{\rm{o}}}{\rm{/J}} \cdot {\rm{mo}}{{\rm{l}}^{ - 1}} = - 68\,640 + 1.28T\left( { \pm 270} \right) \cr} $$ Crystallographic data for all three ternary oxides have been determined based on the thermodynamic information, isobaric phase diagrams and isothermal chemical potential diagrams for the system Pr–Pd –O are developed.

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Orujlu, Elnur N., Ziya S. Aliev, Yasin I. Jafarov, Eldar I. Ahmadov, and Mahammad B. Babanly. "Thermodynamic study of manganese tellurides by the electromotive force method." Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 23, no. 2 (June 4, 2021): 273–81. http://dx.doi.org/10.17308/kcmf.2021.23/3438.

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The thermodynamic properties of manganese tellurides were determined using an electromotive force (EMF) method with a liquid electrolyte in a temperature range from 300 to 450 K. EMF measurements were performed using equilibrium samples taken from the two-phase regions, namely MnTe2 + Te and MnTe + MnTe2, of the Mn–Te system. The phase compositions of all samples were controlled with the X-ray diffraction (XRD) method. The partial molar functions of manganese in alloys, as well as the standard thermodynamic functions of the formation and standard entropies of MnTe and MnTe2, were calculated. A comparative analysis of obtained results with literature data is performed

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Tumidajski, Peter J. "Thermodynamic properties of the Na–Bi–Pb system." Canadian Journal of Chemistry 72, no. 2 (February 1, 1994): 369–71. http://dx.doi.org/10.1139/v94-057.

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Thermodynamic properties of Na in an equimolar Bi–Pb alloy were determined at 723 K for compositions of 0.0075 ≤ XNa ≤ 0.1000 from electromotive force measurements on Na metal concentration cells with a solid Na–β-Al2O3 electrolyte. A coulometric titration technique was used to electrochemically generate the Na metal in the Bi–Pb alloy. The results indicate that, as Na is added to Bi–Pb, the liquid becomes more associated and suggests complex species formation with an ionic character intermediate between those observed for the constituent binaries.

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Imamaliyeva, Samira. "Thermodynamic properties of the GdTe3 compound." Physics and Chemistry of Solid State 22, no. 3 (July 17, 2021): 420–25. http://dx.doi.org/10.15330/pcss.22.3.420-425.

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The alloys of the Gd-Te system in the range of compositions > 75 at% Te were studied by the methods of X-ray diffraction (XRD) and electromotive forces (EMF). From the EMF measurements of the concentration cells relative to the GdTe electrode in the 300-450 K temperature range, the partial thermodynamic functions of GdTe in alloys were determined. By combining these data with the corresponding functions of Gd in GdTe, the partial molar functions of gadolinium in GdTe3+Te alloys, and standard thermodynamic functions of formation and standard entropy of the GdTe3 compound were calculated. The obtained results were compared with the literature data.

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Shishkovskiy, Igor V., Yury G. Morozov, Maxim V. Kuznetsov, and Ivan P. Parkin. "Electromotive force measurements in the combustion wave front during layer-by-layer surface laser sintering of exothermic powder compositions." Physical Chemistry Chemical Physics 11, no. 18 (2009): 3503. http://dx.doi.org/10.1039/b819810a.

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Ateia, E., M. A. Ahmed, and R. M. Ghouniem. "Effect of rare earth substitution on the structural and electrical properties of Cu–Mg ferrite." International Journal of Modern Physics B 29, no. 19 (July 21, 2015): 1550126. http://dx.doi.org/10.1142/s021797921550126x.

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The samples of Cu 0.9 Mg 0.1 R y Fe 2-y O 4, where y = 0.01 and R = Sm , Dy , Ho and Hf , were prepared by standard ceramic method. All investigated samples were sintered at 1150°C with a heating rate of 4°C/min and sintering time of 8 h. X-ray diffraction study of the compositions revealed the formation of cubic spinel structure with the appearance of small peaks indicating the presence of secondary phases. Seebeck coefficient was obtained from thermo-electromotive force (emf) measurements. The alternation of the Seebeck coefficient sign between (+)ve and (-)ve means that the two conduction mechanisms take place simultaneously. The dielectric parameters such as dielectric constant, quality factor were determined as a function of temperature and at different frequencies. The decrease in Fe 3+ ions on the octahedral site decreased the polarization of the system, through the dielectric transition point.

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Park, M., and G. M. Choi. "Composition-Dependent Electrical Conductivity of Ionic-Electronic Composite." MRS Proceedings 500 (1997). http://dx.doi.org/10.1557/proc-500-327.

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ABSTRACTComposition. dependence of electrical conductivity of ionic-electronic composite was camined using yttria(8mol%) stabilized zirconia-NiO composites. The contributions of ectronic and ionic charge carriers to the electrical conductivity were determined by Hebb-Vagner polarization technique and electromotive force measurement of galvanic cell. Up to 6 sol% NiO addition, the conductivity decreased since the electronic NiO acted as an insulator in onic matrix. However the ionic transport was dominant until NiO content reaches 26 vol%. Mixed conduction was observed between 26 and 68 vol% of NiO. The effects of composition on he electrical properties were explained by the microstructure and thus by the distribution of two hases.

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"EVANOHM ALLOY S." Alloy Digest 38, no. 7 (July 1, 1989). http://dx.doi.org/10.31399/asm.ad.ni0373.

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Abstract EVANOHM alloy S offers optimum stability and flexibility with regard to both size and required temperature coefficient of resistance. Its extremely low electromotive force vs copper together with its high electrical resistivity are highly desirable properties in a precision resistance wire. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as joining. Filing Code: Ni-373. Producer or source: Wilbur B. Driver Company.

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Choi, Gyeong Man, Joon Hee Kim, and Young Min Park. "Electrical Conductivity of Ionic and Electronic Mixture." MRS Proceedings 699 (2001). http://dx.doi.org/10.1557/proc-699-r9.6.

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AbstractMixed ionic-electronic conductors (MIECs) which have both ionic and electronic species as charge carriers have a wide range of applications, such as electrodes in fuel cells, electrocatalytic reactors, and gas separating membranes. They may have either electronic or ionic species as the majority charge carriers. In addition to the single-phase mixed conductors, they may be fabricated by mixing two different phases of materials. Although these composites have been less studied than the single phase MIECs, the combined properties are often superior to single phase MIECs, and properties not seen in an individual phase may appear in the composite phase.YSZ-based composite systems were chosen to test the effect of transition-metal-oxide (TMO) addition on the electronic conductivity of composite. To induce mixed conductivity, electronic-conducting TMOs such as NiO and Mn2O3 were added into YSZ above the solubility limit. While the solid solubility of NiO in YSZ is limited that of Mn2O3 is large.In this work, mixed conducting yttria (8 mol%) stabilized zirconia (YSZ) - TMO composites were prepared in full composition range and the electrical conductivity of the composites was measured by 4-probe d.c. conductivity. Electromotive force (emf) measurements of the galvanic cell, current-voltage (I-V) measurements in ion blocking condition and the oxygen-partial-pressure dependent conductivity have been used to determine the contribution of the ionic and electronic charge carriers on the conductivity. Thus the composition-dependent electrical properties were used to explain the percolation behavior of electronic charge carriers in ionic matrix.Although the total conductivity of dense YSZ-TMO composite was variable with TMO content, the partial-electronic conductivity increased and the ionic conductivity decreased. The composition-dependent conductivity was discussed.

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Gärtner, F., R. Busch, P. Haasen, and R. Bormann. "Determination of the Chemical Potentials of Highly Supersaturated Cu-Co Alloys." MRS Proceedings 400 (1995). http://dx.doi.org/10.1557/proc-400-119.

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AbstractWith the CALPHAD approach based on the regular solution model, the thermodynamic functions of the Cu-Co system can be extrapolated to compositions where the homogeneous fee solid solution is thermodynamically unstable. Up to now it has been unclear how reliable such extrapolations are in view of the driving forces for decomposition and whether the Gibbs energy is well described by the model in the unstable region. Therefore, electromotive force measurements were performed to determine directly the chemical potentials of highly supersaturated Cu-Co alloys. Under the prerequisite that time scales of the electrochemical exchange reaction are fast compared with the kinetics of decomposition, the thermodynamics of the alloys can be investigated quasi statically. Within the experimental accuracy the results for both a metastable and an unstable alloy agree well with the calculated chemical potentials. In addition, the experiments demonstrate that the electrochemical cell reaction is reversible upon small external concentration fluctuations of the investigated alloys. Possible reasons for this unexpected stability are discussed taking the kinetics of the decomposition into account.

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Journal articles on the topic 'Electromotive composition'

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