Improved thermoelectric properties of layered Ti1−xNbxS2−ySey solid solutions

The thermoelectric properties of a series of the polycrystalline samples of titanium dichalcogenides with partial substitution of Ti for Nb and S for Se were investigated. It was found that sintering of the samples improved the thermoelectric efficiency (ZT), and the maximum ZT was achieved at sinte...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Ceramic Society 2020-11, Vol.103 (11), p.6289-6297
Main Authors: Romanenko, Anatoly I., Yakovleva, Galina E., Fedorov, Vladimir E., Artemkina, Sofya B., Yu. Ledneva, Alexandra, Zhdanov, Kamil R., Kuchumov, Boris M., Kuznetsov, Vitalii A., Wang, Hongchao, Singh, Sanjai, Saini, Shivani, Han, Mi‐Kyung, Kim, Sung‐Jin
Format: Article
Language:English
Subjects:
Carrier density
Current carriers
electrical conductivity
Electrical resistivity
Electron transport
Figure of merit
low temperature
Recrystallization
Room temperature
Seebeck effect
Sintering
Solid solutions
Thermal conductivity
thermoelectric properties
Thermoelectricity
Titanium
Transport properties
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The thermoelectric properties of a series of the polycrystalline samples of titanium dichalcogenides with partial substitution of Ti for Nb and S for Se were investigated. It was found that sintering of the samples improved the thermoelectric efficiency (ZT), and the maximum ZT was achieved at sintering temperature of 600°C. A further increase in the sintering temperature (850°C and 950°C) led to the recrystallization of the samples, as a result, the Seebeck coefficient sharply decreased and electrical conductivity dramatically increased. The temperature dependences of electrical conductivity σ(T) in the temperature range from 4.2 to 300 K and Seebeck coefficient S(T) in the temperature range from 77 to 300 K were investigated in order to determine the nature of the observed improvements in thermoelectric properties due to double substitutions and sintering. Two‐dimensionalization of electron transport properties of Ti1−xNbxS2−ySey solid solutions was found. The Fermi energy EF2D was estimated using the temperature dependences of Seebeck coefficient. The relationship between the Fermi energy EF2D and figure of merit ZT was established. The effect of sintering on parameters σ(T), S(T), charge carrier concentration (n2D), mobility (µ), and thermal conductivity (k) was found. The optimal value of Fermi energy EF2D in terms of figure of merit ZT = 0.31 at room temperature (T = 300 K) was found for Ti0.98Nb0.02S1.3Se0.7 sample sintered at 600°C.
ISSN:0002-7820
1551-2916
DOI:10.1111/jace.17342