High-temperature thermoelectric properties of polycrystalline CaMn1-Nb O3-δ

Thermoelectric modules built using ceramic legs grown by laser floating zone

“…The maximum values at 923 K observed for the manganite samples (~10-100 S/cm) are in the same order of those obtained for similar CaMnO 3 -based materials [30][31][32]. BBCO samples also present similar conductivities to the ones reported in the literature (~100 S/cm) for laser processed samples [10,23], and higher than for samples prepared by solid-state route (~10-80 S/cm) [33][34][35].…”

“…As it can be observed in the graph, at relatively low temperatures (303 − 732 K) all the fibres show quite linear behaviour, with a mean thermal expansion coefficient of around 12.5-14.0 × 10 −6 /K for the cobaltite, and manganite fibres, respectively (see Table 2). At higher temperatures, the expansion curves show deviations from linearity, which may be attributed to changes in phase composition, the concentration of point defects, or the rearrangement in the sublattices, possibly combined with oxidative decomposition from Mn 4+ to larger Mn 3+ [34], in the manganite fibres. Moreover, the values obtained for these manganites are within the reported in the literature (9-15 × 10 −6 /K) [33,[36][37][38].…”

Effects of calcination temperature and time on the Ca3Co4O9 purity when synthesized using starch-assisted sol-gel combustion method

“…In recent years, utilizing of fossil fuels has shown severe impacts on atmospheric and environmental problems, causing international warming, climate change, greenhouse gas emission, ozone layer depletion, and acid chemical stability. Therefore, they have been recognized as promising thermoelectric materials [4]. However, despite of these advantages, the disadvantage of thermoelectric oxides is their low efficiency (figure of merit).…”

The effect of Sr substitution on the structural and physical properties of manganite perovskites Ca1−xSrxMnO3−δ (0 ≤ x ≤ 1)

“…[21][22][23] Despite the abovementioned applications of the CMO material, the efficiency of this material in thermoelectric applications still needs some improvements specifically in terms of electrical conductivity and Seebeck coefficient. [24][25][26] Furthermore, the lack of good transparency in both UV and visible regions of the light spectrum combined with the drawback of producing thin films limits the applicability of CMO as a suitable electron transport material for photovoltaic cells. 18,27 In addition to thermoelectric and photovoltaic applications, the small band gap (1.1-1.2 eV) of CMO perovskites has hindered their use in photocatalytic applications which require at least a band gap of 1.23 eV.…”