Premium
A comparative study of thermoelectric properties in (Pr,Y)Ba 2 Cu 3 O 7 and PrBa 2 Cu 3 O 7 –Ag percolative systems
Author(s) -
Mori Natsuki,
Okano Hiroyuki,
Furuya Akio
Publication year - 2006
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200669591
Subject(s) - seebeck coefficient , condensed matter physics , electrical resistivity and conductivity , valence (chemistry) , dopant , doping , thermoelectric effect , materials science , variable range hopping , percolation (cognitive psychology) , crystallite , percolation theory , conductivity , thermal conduction , thermodynamics , physics , chemistry , quantum mechanics , neuroscience , biology , metallurgy
Measurements of the temperature‐dependent thermoelectric power S ( T ) and resistivity ρ ( T ) were performed to characterize two kinds of polycrystalline systems (Pr 1– x Y x )Ba 2 Cu 3 O 7 and Ag‐doped PrBa 2 Cu 3 O 7 , each of which exhibits percolative behaviour at a certain doping level. At room temperature, Jonker plots of the thermoelectric power against logarithm of the conductivity in both systems show a similar tendency that two different fitting lines are intercrossed at the percolation thresholds. The ρ ( T ) behaviour below 100 K in each system with low dopant content obeys the variable‐range‐hopping conduction. Variations of S ( T ) in both systems could be reconciled with the Boson–Fermion theory based on the resonating‐valence‐bond model with reasonable dependences of fitting parameters upon doping. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)