Suppression of intrinsic thermal conductivity in Sr1-x Gd x TiO3 ceramics via phonon-point defect scattering for enhanced thermoelectric application.
RSC Adv
; 13(1): 665-673, 2022 Dec 19.
Article
em En
| MEDLINE
| ID: mdl-36605633
ABSTRACT
A substantial reduction in the thermal conductivity for strontium titanate (ABO3) perovskite structure was realized for the A-site substitution of gadolinium (rare earth element) in SrTiO3 ceramics. The effect of Gd3+ substitution on the structure, composition, and thermoelectric properties of SrTiO3 was investigated. The substitution of Gd3+ in the SrTiO3 matrix resulted in the minimalization of thermal conductivity. The thermal conductivity followed a similar trend as that of thermal diffusivity, but specific heat capacity exhibited a non-monotonic trend. The thermal conductivity is reduced to 1.05 W m-1 K-1 for the minimal substitutional composition (Sr0.99Gd0.01TiO3) which is 30% less than that of SrTiO3 at 303 K. The variation in the ionic radii and atomic mass of the heavier rare earth Gd3+ substituted over Sr2+ resulted in the reduction of thermal conductivity of SGTO ceramics caused by the corresponding boundary scattering at low temperatures and temperature-independent phonon-impurity scattering at high temperatures.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2022
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Article