Large Seebeck coefficients in La2NiO4+δ with tuned δ values. (2018)

• Record Type: Journal Article
• Authors: Serrano-Sánchez, F.; Pinacca, R.; Troncoso, L.; Nemes, N.M.; Martínez, J.L.; Alonso, J.A.
• Is Part Of: Materials today. Volume 5:Number 4(2018)Part 1
• Page Start: 10203
• Page End: 10210
• Publication Date: 2018
• Subjects: Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2017.12.266
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Ab-initio studies showed that large Seebeck coefficients could be achieved in La2 NiO4+ δ layered perovskite oxide by tuning its oxygen content. We have prepared La2 NiO4+δ by soft-chemistry procedures and annealed the samples under different conditions (atmospheres and temperatures), yielding samples with extra oxygen content (δ) in the 0.09-0.30 range. The exact stoichiometry of the samples was determined by iodometry and by a neutron powder diffraction analysis for a selected sample. Thermoelectric properties were studied and the thermopower was measured in the differently treated samples. Thermopower as high as S= 250 μV K -1 at T= 100 K and low thermal conductivity values as low as 0.8 W m -1 K -1 at room temperature have been obtained in La2 NiO4+δ polycrystalline samples with δ= 0.094.