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Structural features and thermoelectric properties of Al‐doped (ZnO) 5 In 2 O 3 homologous phases
Author(s) -
Košir Mateja,
Čeh Miran,
OwYang Cleva W.,
Guilmeau Emmanuel,
Bernik Slavko
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14878
Subject(s) - materials science , homologous series , doping , thermoelectric effect , sintering , octahedron , microstructure , electrical resistivity and conductivity , analytical chemistry (journal) , crystallography , conductivity , phase (matter) , mineralogy , crystal structure , metallurgy , chemistry , thermodynamics , optoelectronics , physics , organic chemistry , chromatography , electrical engineering , engineering
In this work, we investigated the influence of Al doping on the structure of the (ZnO) 5 In 2 O 3 homologous phase and the thermoelectric characteristics of (ZnO) 5 (In 1− x Al x ) 2 O 3 ceramics for x =0, 0.01, 0.03, 0.05, 0.1, and 0.2, prepared using a classic ceramic procedure and sintering at 1500°C for 2 hours. The Al substituted for In on both the primary sites in the Zn 5 (In 1− x Al x ) 2 O 8 homologous phase, the octahedral sites in the basal‐plane inversion boundaries and the trigonal bi‐pyramidal sites in the zig‐zag inversion boundaries, which resulted in a uniformly increased shrinkage of the unit cell with the additions of Al. The a and c parameters were reduced for x =0.2 by a maximum 0.8%. All the samples had similar microstructures, so the differences in the TE characteristics mainly resulted from the effects of the substitution of Al for In, decreasing the charge‐carrier concentration and affecting their mobility. Slightly improved TE characteristics were only observed for Al additions with x =0.01‐0.05, while larger additions of Al only resulted in a reduced electrical conductivity and decreased ZT values in comparison to the un‐doped composition.