Exploring the Thermoelectric Performance of BaGd2NiO5 Haldane Gap Materials
authors Nasani, N; Rocha, CMO; Kovalevsky, AV; Irurueta, GO; Populoh, S; Thiel, P; Weidenkaff, A; da Silva, FN; Fagg, DP
nationality International
journal INORGANIC CHEMISTRY
keywords DEFICIENT SRTIO3 CERAMICS; CRYSTAL-STRUCTURE; POWER-GENERATION; HIGH-FIGURE; THIN-FILMS; R2BANIO5 R; CA3CO4O9; OXIDES; CHAIN; SPECTROSCOPY
abstract One-dimensional Haldane gap materials, such as the rare earth barium chain nickelates, have received great interest due to their vibrant one-dimensional spin antiferromagnetic character and unique structure. Herein we report how these ID structural features can also be highly beneficial for thermoelectric applications by analysis of the system CaxBaGd(2-x)NiO(5) 0 <= x <= 0.25. Attractive Seebeck coefficients of 140-280 mu V K-1 at 350-1300 K are retained even at high acceptor -substitution levels, provided by the interplay of low dimensionality and electronic correlations. Furthermore, the highly anisotropic crystal structure of Haldane gap materials allows very low thermal conductivities, reaching only 1.5 W m(-1) K-1 at temperatures above 1000 K, one of the lowest values currently documented for prospective oxide therrnoelectrics. Although calcium substitution in BaGd2NiO5 increases the electrical conductivity up to 5-6 S cm(-1) at 1150 K < T < 1300 K, this level remains insufficient for thermoelectric applications. Hence, the combination of highly promising Seebeck coefficients and low thermal conductivities offered by this 1D material type underscores a potential new structure type for thermoelectric materials, where the Main challenge will be to engineer the electronic band structure and, probably, microstructural features to further enhance the mobility of the charge carriers.
publisher AMER CHEMICAL SOC
issn 0020-1669
isbn 1520-510X
year published 2017
volume 56
issue 4
beginning page 2354
ending page 2362
digital object identifier (doi) 10.1021/acs.inorgchem.7b00049
web of science category Chemistry, Inorganic & Nuclear
subject category Chemistry
unique article identifier WOS:000394736600064
  ciceco authors
  impact metrics
times cited (wos core): 2
journal impact factor (jcr 2016): 4.857
5 year journal impact factor (jcr 2016): 4.503
category normalized journal impact factor percentile (jcr 2016): 92.391
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