Cationic Effect on Electrical Conductivity and Viscosity of Alkaline‐Earth Silicate Melts: Phenomenology

2015 ◽  
Vol 98 (8) ◽  
pp. 2438-2444 ◽  
Author(s):  
Yong‐Uk Han ◽  
Dong Joon Min
Keyword(s):  
Electrical Conductivity ◽  
Alkaline Earth ◽  
Silicate Melts ◽  
Cationic Effect

scholarly journals Behavior and properties of water in silicate melts under deep mantle conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bijaya B. Karki ◽  
Dipta B. Ghosh ◽  
Shun-ichiro Karato
Keyword(s):  
Electrical Conductivity ◽  
Molar Volume ◽  
Water Solution ◽  
Pure Water ◽  
Electrical Conductance ◽  
Water Structure ◽  
Bulk Water ◽  
Silicate Melts ◽  
Pressure Regime ◽  
Low Pressures

AbstractWater (H2O) as one of the most abundant fluids present in Earth plays crucial role in the generation and transport of magmas in the interior. Though hydrous silicate melts have been studied extensively, the experimental data are confined to relatively low pressures and the computational results are still rare. Moreover, these studies imply large differences in the way water influences the physical properties of silicate magmas, such as density and electrical conductivity. Here, we investigate the equation of state, speciation, and transport properties of water dissolved in Mg1−xFexSiO3 and Mg2(1−x)Fe2xSiO4 melts (for x = 0 and 0.25) as well as in its bulk (pure) fluid state over the entire mantle pressure regime at 2000–4000 K using first-principles molecular dynamics. The simulation results allow us to constrain the partial molar volume of the water component in melts along with the molar volume of pure water. The predicted volume of silicate melt + water solution is negative at low pressures and becomes almost zero above 15 GPa. Consequently, the hydrous component tends to lower the melt density to similar extent over much of the mantle pressure regime irrespective of composition. Our results also show that hydrogen diffuses fast in silicate melts and enhances the melt electrical conductivity in a way that differs from electrical conduction in the bulk water. The speciation of the water component varies considerably from the bulk water structure as well. Water is dissolved in melts mostly as hydroxyls at low pressure and as –O–H–O–, –O–H–O–H– and other extended species with increasing pressure. On the other hand, the pure water behaves as a molecular fluid below 15 GPa, gradually becoming a dissociated fluid with further compression. On the basis of modeled density and conductivity results, we suggest that partial melts containing a few percent of water may be gravitationally trapped both above and below the upper mantle-transition region. Moreover, such hydrous melts can give rise to detectable electrical conductance by means of electromagnetic sounding observations.

Electrical Conductivity and Thermodynamic Properties of Some Alkaline Earth-Doped Lanthanum Chromites

2005 ◽  
Vol 26 (2) ◽  
pp. 543-557 ◽  
Author(s):  
S. Tanasescu ◽  
A. Orasanu ◽  
D. Berger ◽  
I. Jitaru ◽  
J. Schoonman
Keyword(s):  
Electrical Conductivity ◽  
Thermodynamic Properties ◽  
Alkaline Earth ◽  
Lanthanum Chromites

scholarly journals Cation Distribution and Electrical Conductivity in BaxSryLa0.50InO2.25+x+y System with Excess Alkaline Earth Oxide

2006 ◽  
Vol 114 (1329) ◽  
pp. 399-403
Author(s):  
Katsuyoshi KAKINUMA ◽  
Tooru ARISAKA ◽  
Hiroshi YAMAMURA ◽  
Tooru ATAKE
Keyword(s):  
Electrical Conductivity ◽  
Cation Distribution ◽  
Alkaline Earth ◽  
Alkaline Earth Oxide

scholarly journals Influence of alkaline-earth metal substitution on structure, electrical conductivity and oxygen transport properties of perovskite-type oxides La0.6A0.4FeO3−δ (A = Ca, Sr and Ba)

2020 ◽  
Vol 22 (21) ◽  
pp. 11984-11995 ◽  
Author(s):  
Jia Song ◽  
De Ning ◽  
Henny J. M. Bouwmeester
Keyword(s):  
Electrical Conductivity ◽  
Transport Properties ◽  
Oxygen Transport ◽  
Electrical Conduction ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Perovskite Oxides ◽  
Alkaline Earth Metal ◽  
Metal Substitution ◽  
Perovskite Type

Revisiting the electrical conduction and oxygen transport properties of alkaline-earth metal substituted La0.6A0.4FeO3−δ (A = Ca, Sr and Ba) perovskite oxides.

Synthesis and High Temperature Thermoelectric Properties of Alkaline-Earth Metal Hexaborides MB6 (M=Ca, Sr, Ba)

2003 ◽  
Vol 793 ◽  
Author(s):  
Masatoshi Takeda ◽  
Yosuke Kurita ◽  
Keisuke Yokoyama ◽  
Takahiro Miura ◽  
Tsuneo Suzuki ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Thermoelectric Device ◽  
Alloying Effect ◽  
P Type

ABSTRACTPolycrystalline alkaline-earth hexaborides (MB6: M =Ca, Sr, Ba) were synthesized and their thermoelectric and transport properties were examined to discuss their possibility as high temperature thermoelectric materials. Hall measurements showed that carrier concentration of the BaB6 was the highest among the three hexaborides and that of CaB6 was the lowest. Substitution of part of the alkaline earth metals with one of the others changed the carrier concentration of the hexaboride. As the carrier concentration increased, Seebeck coefficient increased and electrical conductivity decreased. These results suggest that the thermoelectric properties of the divalent hexaborides depend largely on the carrier concentration, and optimum carrier concentration which gives maximum power factor was estimated to be approximately 2x1026 m−3. Consequently, such a substitution enables us to control Seebeck coefficient and electrical conductivity of the hexaborides, and will also be effective to reduce the lattice heat conduction due to the alloying effect. A thermoelectric device was fabricated using SrB6 and boron carbide thin films as n-type and p-type elements, respectively. To the best of our knowledge, this is the first demonstration of a thermoelectric device composed of only boron-rich solids.

scholarly journals Percolative conductivity in alkaline-earth silicate melts and glasses

2003 ◽  
Vol 64 (5) ◽  
pp. 661-667 ◽  
Author(s):  
M Malki ◽  
M Micoulaut ◽  
F Chaimbault ◽  
Y Vaills ◽  
P Simon
Keyword(s):  
Alkaline Earth ◽  
Silicate Melts

On the Electrical Conductivity of Some Alkaline Earth Titanates

1953 ◽  
Vol 21 (5) ◽  
pp. 801-806 ◽  
Author(s):  
E. K. Weise ◽  
I. A. Lesk
Keyword(s):  
Electrical Conductivity ◽  
Alkaline Earth

The electrical conductivity of silicate melts: systems containing Ca, Mn and Al

1948 ◽  
Vol 4 ◽  
pp. 265 ◽  
Author(s):  
J. O'M. Bockris ◽  
J. A. Kitchener ◽  
S. Ignatowicz ◽  
J. W. Tomlinson
Keyword(s):  
Electrical Conductivity ◽  
Silicate Melts
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