Journal ArticleDOI
High-temperature resistivity and thermopower studies on substituted Bi-2212 and Bi-2201 systems
V. Ponnambalam,U.V. Varadaraju +1 more
TLDR
In this article, the resistivity and thermopower of semiconducting phases in the system Bi 2 Sr 2 Ca 1− x Y x Cu 2 O 8+δ and Bi 2 S 2 La x CuO 6 +δ have been measured in the temperature ranges 300-700 K and 300-1000 K respectively.Abstract:
The resistivity (ϱ) and thermopower ( S ) of semiconducting phases in the system Bi 2 Sr 2 Ca 1− x Y x Cu 2 O 8+δ and Bi 2 Sr 2− x La x CuO 6+δ have been measured in the temperature ranges 300–700 K and 300–1000 K respectively. The values of ϱ and S at any temperature increase with increase in x . Both systems show thermally activated hopping at low temperatures (300–450 K) with the activation energy increasing with x . The figure of merit ( S 2 σ/λ) peaks to a maximum value of 1.9×10 -5 WK -2 m -1 at x =0.7 in the Bi-2212 system.read more
Citations
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Journal ArticleDOI
Effect of Y3+ substitution for Ca on the transport and mechanical properties of Bi2Sr2Ca1-xYxCu2O8+δ system
TL;DR: In this article, the influence of substitution of composition elements on the thermoelectric power and microhardness of Bi 2 Sr 2 Ca 1− x Y x Cu 2 O 8+ δ, with 0.0≤ x ≤ 0.75, was investigated.
Journal ArticleDOI
High-temperature thermoelectric properties of the sintered Bi2Sr2Ca1 − xYxCu2Oy (x = 0 – 1)
M. Yasukawa,N. Murayama +1 more
TL;DR: In this article, the authors measured electrical conductivity and Seebeck coefficient in a temperature range of 320-1073 K for sintered samples of Bi2Sr2Ca1 − xYxCu2Oy (x = 0, 0.8, 1.7-3.0), and found that the conduction behavior changes from n-type metallic to p-type semiconducting with increasing yttrium concentration.
Journal ArticleDOI
Na-Site Doping of NaCo2O4 Thermoelectric Materials
TL;DR: The maximum power factors of the K, Ca, Sr and Ce doped and non-doped γ-NaxCo2O4 oxides were respectively 2.04, 1.93 and 1.9 W·m-1·K-2 as discussed by the authors.
References
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Journal ArticleDOI
Materials for thermoelectric energy conversion
TL;DR: The field of thermoelectric energy conversion is reviewed from both a theoretical and an experimental standpoint in this paper, with particular emphasis being placed on the most recent developments in high-temperature semiconductors.
Journal ArticleDOI
Physical properties of Bi 2 Sr 2 Ca n − 1 Cu n O y ( n =1,2,3)
TL;DR: The superconducting properties, magnetic susceptibilities, Hall coefficients, and infrared optical reflection spectra were measured after sufficient characterization of the samples and the antiferromagnetic semiconductor semiconductor normal-metal transition was observed with increasing hole concentration.
Journal ArticleDOI
Variation of Tc and transport properties with carrier concentration in Y- and Pb-doped Bi-based superconductors.
TL;DR: Analysis of the electrical resistivity in the insulating region suggests that the transport is governed by a variable-range-hopping mechanism in the low-temperature region and phonon-assisted hopping of polarons in the high-tem temperature region.
Journal ArticleDOI
Scaling behavior at the insulator-metal transition in Bi2Sr2(CazR1-z)Cu2O8+y where R is a rare-earth element.
C. Quitmann,D. Andrich,C. Jarchow,M. Fleuster,Bernd Beschoten,Gernot Güntherodt,Victor Moshchalkov,G. Mante,R. Manzke +8 more
TL;DR: The resistivity in the insulating regime is analyzed using a generalized hopping approach based on the connectivity criterion, which enables us to estimate the dependence of the localization radius a H on the Ca concentration independent of dimensionality.
Journal ArticleDOI
Superconducting and magnetic phase boundaries in Bi2Sr2Ca1-xMxCu2O8, with M=Y, Gd, and Pr.
Y. Gao,P. Pernambuco-Wise,J. E. Crow,J. W. O’Reilly,Nicholas D. Spencer,H. Chen,R. E. Salomon +6 more
TL;DR: The dominant suppression mechanism in all three cases is driven by the filling of the Cu 3d hole by the extra electron and the breaking of theCu 3d\char21{}O 2p hybridization.