Thermoelectric properties of CeNi2Al3 compound: an experimental and theoretical study

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2019-11, Vol.125 (11), p.1-6, Article 757
• Main Authors: Szajek, A., Kowalczyk, A.
• Format: Article
• Language: English
• Subjects: Aluminum; Applied physics; Bismuth tellurides; Characterization and Evaluation of Materials; Coherent potential approximation; Condensed Matter Physics; Density functional theory; Electrical resistivity; Figure of merit; Machines; Manufacturing; Materials science; Mathematical analysis; Nanotechnology; Nickel; Optical and Electronic Materials; Organic chemistry; Physics; Physics and Astronomy; Power factor; Processes; Seebeck effect; Surfaces and Interfaces; Temperature; Temperature dependence; Thermal conductivity; Thermoelectric materials; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-019-3057-z

We present thermoelectric properties of the CeNi 2 Al 3 compound in the temperature range from 4 to 300 K. The electrical resistance ( ρ ) exhibits a metallic-like character reaching approximately 50 μΩ cm at room temperature. The temperature dependence of the Seebeck coefficient ( S ) is typical for mixed valence compounds having positive values with a broad maximum (~ 46 μV/K) over a wide temperature range from 200 to 300 K. The thermal conductivity ( κ ) value reaches 15 W/(m K) at T  = 300 K. The power factor ( PF  =  S 2 / ρ ) at 150 K is high (~ 70 μW/cm K 2 ), larger than for conventional thermoelectric materials based on Bi 2 Te 3 . The dimensionless figure of merit ( ZT) has a broad maximum over a wide temperature range, which reaches the value of 0.1 around 220 K. The experimental results are supported by calculations within the density functional theory (DFT) performed on the basis of the full-potential local-orbital minimum-basis scheme (FPLO). The coherent potential approximation (CPA) is used to simulate the chemical disorder. The calculations are focused on the site preference of Ni and Al atoms. Investigations of the energetic stability have shown that in CeNi 2 Al 3 the aluminum atoms prefer the 3 g sites and the nickel ones the 2 c sites.