Structural characterization and transport properties of the HTc Bi2Sr2(Ca,Cd)Cu2O8+δ glass-ceramic rods

摘要: Abstract In this study, structural and transport properties including electrical resistance (R–T) thermoelectric power (S–T) thermal conductivity (κ–T), for the glass-ceramic rods of Bi2Sr2Ca1−xCdxCu2O8+δ with 0 ≤ x ≤ 0.8 were investigated. XRD SEM-EDX investigations showed multiphase, complex deformed structure in Cd-substituted samples. An increase a-axis decrease c-axis obtained. All samples metallic trend between 300 K Tc but value decreased significantly increasing Cd concentration system. The hole per Cu was calculated by using Presland method increased substitution level. values, S, are obtained to be positive found almost linearly decreasing temperature, reaching a maximum around Tc. With reducing temperature further, is fall rapidly zero. Magnitude S decreases results have been analyzed terms “Two band model linear T-term” “Xin's two model”. excellent agreement Two T-term data has considerable effect on conductivity, κ. magnitude κ suppressed when increased. A sharp rising just below all samples, suggesting that impurities play an important role heat due electron–phonon-impurity scattering rate.