The resistivity (ρ{variant}) and thermopower (S) of semiconducting phases in the system Bi2Sr2Ca1-xYxCu2O8+δ and Bi2Sr2-xLaxCuO6+δ have been measured in the temperature ranges 300-700 K and 300-1000 K respectively. The values of ρ{variant} 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 (S2σ/λ) peaks to a maximum value of 1.9×10-5 WK-2m-1 at x=0.7 in the Bi-2212 system. © 1994.

Upadhyayula V Varadaraju

Department Of Chemistry

Bismuth compounds

Copper oxides

Crystallization

High temperature properties

Low temperature operations

Superconductivity

Thermal effects

Thermal variables measurement

Activation energy

High temperature resistivity

OXYGEN STOICHIOMETRY

SEMICONDUCTING PHASE

Thermally activated hopping

Thermopower

Variable range hopping

High temperature superconductors

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High-temperature resistivity and thermopower studies on substituted Bi-2212 and Bi-2201 systems

Physica C: Superconductivity and its applications

Systematic studies of the Bi-2212 superconducting phase, substituting at the Cu-site by Fe and Co, have been carried out on an off-stoichiometric composition Bi2.1Sr1.93Ca0.97(Cu2 - xMx)O8 + y(M = Fe, Co; 0 ≤ x ≤ 0.12 for Fe and 0 ≤ x ≤ 0.1 for Co). For the x = 0 phase, Tc,zero values in the range 74-76 K have been obtained consistently. X-ray diffraction studies show that the solid solubility exists up to x = 0.12 for M = Fe and x = 0.1 for M = Co. A monotonic decrease in Tc with increasing dopant concentration is observed from resistivity as well as AC susceptibility measurements, and the results are discussed. © 1993.

Structure and superconductivity studies on Fe and Co doped Bi-2212

Physical Review B

Thermoelectric power of theBi2Sr2Ca1−xYxCu2O8+y(x=0–1.0) system

Thermoelectric power ofBi2Sr2Ca1−xYxCu2O8+y

Superconducting and magnetic phase boundaries inBi2Sr2Ca1−xMxCu2O8, withM=Y, Gd, and Pr

Materials Science and Engineering: B

Comment on “on the use of oxides for thermoelectric refrigeration”

Journal	Physica C: Superconductivity and its applications
ISSN	09214534
Open Access	No