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Thermoelectric Properties of Reduced Polycrystalline Sr 0.5 Ba 0.5 Nb 2 O 6 Fabricated Via Solution Combustion Synthesis
Author(s) -
Dandeneau Christopher S.,
Bodick Tyler W.,
Bordia Rajendra K.,
Ohuchi Fumio S.
Publication year - 2013
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.12319
Subject(s) - seebeck coefficient , materials science , analytical chemistry (journal) , thermoelectric effect , crystallite , electrical resistivity and conductivity , x ray photoelectron spectroscopy , atmospheric temperature range , figure of merit , thermal conductivity , mineralogy , metallurgy , chemistry , nuclear magnetic resonance , thermodynamics , optoelectronics , composite material , physics , chromatography , electrical engineering , engineering
The thermoelectric properties of bulk polycrystalline Sr 0.5 Ba 0.5 Nb 2 O 6 ( SBN 50) fabricated via solution combustion synthesis ( SCS ) and reduced at temperatures of 900°C–1150°C were explored. The Seebeck coefficient ( S ) of all samples increased over the entire range of testing temperatures; a peak S value of −281 μV/K was obtained at 930 K for the sample reduced at 900°C. A metal‐insulator transition was observed in the electrical conductivity (σ) of samples reduced at 1000°C–1150°C, whereas only semiconducting electrical behavior was observed for the sample reduced at 900°C. An optimal balance between S and σ was achieved for the pellet reduced at 1000°C, which exhibited a maximum power factor of 1.78 μW/cm·K 2 at 930 K. Over a temperature range of 300–930 K, the thermal conductivity (κ) of as‐processed and reduced (1000°C) SBN 50 was found to be 1.03–1.4 and 1.46–1.84 W/m·K, respectively. A maximum figure of merit ( ZT ) of 0.09 was obtained at 930 K for the 1000°C‐reduced sample. X ‐ray photoelectron spectroscopy revealed that the Nb 2+ peak intensity increased at higher reduction temperatures, which could possibly lead to a distortion of NbO 6 octahedra and a decrease in the Seebeck coefficient.