Enhanced thermopower and low thermal conductivity in p-type polycrystalline ZrTe5

• Published in: Applied physics letters Vol. 111; no. 5
• Main Authors: Hooda, M. K., Yadav, C. S.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 31-07-2017
• Subjects: Applied physics; Carrier density; Electrical resistivity; Figure of merit; Heat conductivity; Heat transfer; Intermetallic compounds; Polycrystals; Thermal conductivity; Thermoelectricity
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4997460

Thermoelectric properties of polycrystalline p-type ZrTe5 are reported in the temperature (T) range of 2–340 K. Thermoelectric power (S) is positive and reaches up to 458 μV/K at 340 K on increasing T. The value of Fermi energy 16 meV suggests a low carrier density of ≈9.5 × 1018 cm−3. A sharp anomaly in S data is observed at 38 K, which seems intrinsic to p-type ZrTe5. The thermal conductivity (κ) value is low (2 W/m K at T = 300 K) with major contribution from the lattice part. Electrical resistivity data show the metal to semiconductor transition at T ∼ 150 K and non-Arrhenius behavior in the semiconducting region. The figure of merit zT (0.026 at T = 300 K) is ∼63% higher than that of HfTe5 (0.016) and better than those of the conventional SnTe, p-type PbTe, and bipolar pristine ZrTe5 compounds.