Electrical conductivity and Seebeck coefficients of (La, Ca) (Cr, Co) O3 were measured as a function of temperature. The electrical conductivity as measured in air from 100 to 1100-degrees-C increased with increasing Co and Ca content. The Seebeck coefficients were positive, indicating p-type conductivity. The substitution of Co for Cr significantly decreased the Seebeck coefficients, indicating that the substitution resulted in an increase in site occupancy, associated with the Co. The additional Ca substitution for La resulted in further decrease in the Seebeck coefficients, then exhibited a temperature-independent behaviour, indicating that the carrier mobility, rather than carrier concentration, was thermally activated. The activation energies were 0.18 and 0.25 eV for LaCrO3 and LaCoO3, respectively, and increased to about 0.50 eV with substitution of 10 mol % Co for Cr and then linearly decreased as Co content increased.


Electrical properties and photoconductivity of polyaniline/sulfonated poly(arylene ether sulfone) composite films
Sankir, Nurdan D.; Sankir, Mehmet; Parlak, Mehmet (Springer Science and Business Media LLC, 2009-05-01)
Temperature dependent electrical conductivity of the polyaniline-sulfonated poly(arylene ether sulfone) with 35 mol percent sulfonation (PANI-BPS35) composite films were investigated in the temperature range of 80-380 K. These composite films showed semiconductor behavior with the exponential variation of inverse temperature dependence of electrical conductivity. Calculated Mott's parameters showed that variable range hopping mechanism is the dominant transport mechanism for the carriers in low temperature ...
Crystallization kinetics of fluorophosphate glasses .1. Effect of composition and hearing rate
Ozturk, A (Springer Science and Business Media LLC, 1997-05-15)
Crystallization behaviour of glasses from the system AlF3-MF2-Ba(PO3)(2) (M = Ca, Mg, Sr, Ba) have been studied using differential thermal analysis as a function of Ba(PO3)(3). The kinetic parameters for crystallization, namely, the activation energy, E frequency factor, v, and Avrami exponent, n, were determined. E,v and n decreased with increasing Ba(PO3)(2). Crystallization commenced at higher temperatures and the crystal growth mechanism changed from bulk to surface with increasing Ba(PO3)(2). X-ray dif...
Trapping centers and their distribution in Tl2InGaSe4 single crystals by thermally stimulated luminescence
Delice, S.; IŞIK, MEHMET; Hasanlı, Nızamı (Springer Science and Business Media LLC, 2014-03-01)
Thermoluminescence (TL) measurements in Tl2InGaSe4-layered single crystals have been carried out in the temperature range of 10-200 K at various heating rates (0.2-1.0 K s(-1)) to get information about the characteristics of traps. Two TL overlapping glow peaks related to defect levels have been clearly observed. Thermal cleaning procedure was applied to the glow curves to separate overlapped peaks. Initial rise, peak shape, and heating rate methods were used to calculate the activation energies of the reve...
Hot-pressed hydroxylapatite/monoclinic zirconia composites with improved mechanical properties
Evis, Zafer (Springer Science and Business Media LLC, 2007-04-01)
Composites of hydroxylapatite (HA) and monoclinic zirconia were hot-pressed at 1100 degrees C and 1200 degrees C under vacuum to study the phase transformations and the mechanical properties. X-ray diffraction results showed a higher phase transformation from monoclinic-ZrO2 to tetragonal-ZrO2 when the sintering temperature increased from 1100 degrees C to 1200 degrees C. HA decomposed faster when the amount of ZrO2 in the composites increased. Moreover, small amount of alpha-TCP and CaZrO3 was observed in ...
Growth, electrical and structural characterization of beta-GaSe thin films
Parlak, Mehmet; Ercelebi, C (Springer Science and Business Media LLC, 2003-04-01)
GaSe thin films were deposited onto the glass substrates kept at 200degrees and 300degreesC by the thermal evaporation of GaSe crystals under the pressure of 10(-5) Torr. X-ray analysis of the films revealed that films grown at 200. C are amorphous in nature while the films grown at 300degreesC are polycrystalline beta-GaSe. The temperature dependent electrical conductivity measurements in the region of 320-100 K for the films grown at 300degreesC showed that the transport mechanisms are the thermionic emis...
Citation Formats
R. KOC and H. ANDERSON, “ELECTRICAL-CONDUCTIVITY AND SEEBECK COEFFICIENT OF (LA, CA) (CR, CO)O3,” JOURNAL OF MATERIALS SCIENCE, pp. 5477–5482, 1992, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64833.