English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Rare-earth pyrochlores, commonly exhibiting anomalously low lattice thermalconductivities, are considered as promising topcoat materials for thermalbarrier coatings. However the structural origin underlying their low thermalconductivities remain unclear. In the present study, we investigated the phononproperties of two groups of RE pyrochlores, Ln2Zr2O7 (Ln = La, Nd, Sm, Gd) andGd2T2O7 (T = Zr, Hf, Sn, Pb) employing density functional theory and quasiharmonic approximation. Through the relaxation time approximation (RTA) withDebye model, the thermal conductivities of those RE pyrochlores were predicted,showing good agreement with experimental measurements. The low thermalconductivities of RE pyrochlores were shown to largely come from theinterference between the low-lying optical branches and acoustic branches. Thestructural origin underlying the low-lying optical branches was then clarifiedand the competition between scattering processes in transverse and longitudeacoustic branches was discussed.

The Role of Low-lying Optical Phonons in Lattice Thermal Conductance of Rare-earth Pyrochlores: A First-principle Study