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Thermoelectric properties of Yb and Nb codoped CaMnO 3
Author(s) -
Kabir Rezaul,
Zhang Tianshu,
Donelson Richard,
Wang Danyang,
Tian Ruoming,
Tan Thiam Teck,
Gong Bin,
Li Sean
Publication year - 2014
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.201330475
Subject(s) - dopant , thermoelectric effect , materials science , doping , thermal conductivity , perovskite (structure) , phonon , analytical chemistry (journal) , electrical resistivity and conductivity , crystallography , condensed matter physics , chemistry , thermodynamics , optoelectronics , physics , chromatography , quantum mechanics , composite material
Perovskite‐type Ca 1− x Yb x Mn 0.98 Nb 0.02 O 3 ( x = 0, 0.02, 0.05, 0.08, and 0.1) thermoelectric materials were synthesized by a solid‐state reaction technique. The dopant‐level dependence of lattice parameter, the correlation of crystallographic structures and the high temperature properties of these codoped CaMnO 3 systems were investigated. The results show that codoping in A and B‐sites of the perovskite structure improves the ZT value noticeably rather than the single doping. This is driven by the compromise among carrier concentration, structural distortion, and phonon impediment. The increase of Yb doping leads to higher phonon impediment and consequently reduces thermal conductivity. In this codoping system, the effective doping content is x = 0.05 in order to reduce the thermal conductivity. The sample with nominal composition of Ca 0.95 Yb 0.05 Mn 0.98 Nb 0.02 O 3 reaches the highest ZT of 0.13 at 973 K, which is almost 18% higher than that of the single‐doped CaMn 0.98 Nb 0.02 O 3 .