Reduced thermal conductivity by nanoscale intergrowths in perovskite like layered structure La2Ti2O7

Khaliq, Jibran, Li, Chunchun, Chen, Kan, Shi, Baogui, Ye, Haitao, Grande, Antonio, Yan, Haixue and Reece, Michael (2015) Reduced thermal conductivity by nanoscale intergrowths in perovskite like layered structure La2Ti2O7. Journal of Applied Physics, 117 (7). 075101. ISSN 0021-8979

Preview

Text Reduced thermal conductivity by nanoscale intergrowths in perovskite like layered structure La2Ti2O7.pdf - Published Version Download (1MB) | Preview

Abstract

The effect of substitution and oxidation-reduction on the thermal conductivity of perovskite-like layered structure (PLS) ceramics was investigated in relation to mass contrast and non-stoichiometry. Sr (acceptor) was substituted on the A site, while Ta (donor) was substituted on the B site of La2Ti2O7. Substitution in PLS materials creates atomic scale disorders to accommodate the non-stoichiometry. High resolution transmission electron microscopy and X ray diffraction revealed that acceptor substitution in La2Ti2O7 produced nanoscale intergrowths of n = 5 layered phase, while donor substitution produced nanoscale intergrowths of n = 3 layered phase. As a result of these nanoscale intergrowths, the thermal conductivity value reduced by as much as ∼20%. Pure La2Ti2O7 has a thermal conductivity value of ∼1.3 W/m K which dropped to a value of ∼1.12 W/m K for Sr doped La2Ti2O7 and ∼0.93 W/m K for Ta doped La2Ti2O7 at 573 K.

Actions (login required)

View Item

Downloads