The ultra-low glasslike thermal conductivities of Y3+- and Ce4+- codoped lanthanum zirconate pyrochlores for potential thermal barrier coating applications
{"title":"The ultra-low glasslike thermal conductivities of Y3+- and Ce4+- codoped lanthanum zirconate pyrochlores for potential thermal barrier coating applications","authors":"","doi":"10.1016/j.jeurceramsoc.2024.117038","DOIUrl":null,"url":null,"abstract":"<div><div>It is urgent to develop thermal barrier coating (TBC) topcoat materials with ultra-low thermal conductivities for next-generation gas turbine engines. A novel pyrochlore-based single-phased ceramic, tuned by codoping of lanthanum zirconate, (La<sub>1-x</sub>Y<sub>x</sub>)<sub>2</sub>(Zr<sub>1-y</sub>Ce<sub>y</sub>)<sub>2</sub>O<sub>7</sub>, has been synthesized from the solid state reaction method. The thermal conductivity of (La<sub>1-x</sub>Y<sub>x</sub>)<sub>2</sub>(Zr<sub>1-y</sub>Ce<sub>y</sub>)<sub>2</sub>O<sub>7</sub> not only exhibits a temperature-independent trend but also reaches as low as 0.93 W·m<sup>−1</sup>·K<sup>−1</sup>, a value that is lowest of fully dense crystalline solids in open literature, attributing to the following two combined effects. The first is the strong scattering of phonons by small-sized Y<sup>3+</sup> cations occupying the oversized atomic cages formed by the distinctive pyrochlore structure. The second is the lattice softening effects arising from larger-sized Ce<sup>4+</sup> substituting Zr<sup>4+</sup> cations. The above two effects act in concert and thus form a glasslike and ultra-low thermal conductivity of (La<sub>1-x</sub>Y<sub>x</sub>)<sub>2</sub>(Zr<sub>1-y</sub>Ce<sub>y</sub>)<sub>2</sub>O<sub>7</sub> solid solutions, which is ideal for next-generation TBC topcoat applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":null,"pages":null},"PeriodicalIF":5.8000,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The European Ceramic Society","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0955221924009117","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
It is urgent to develop thermal barrier coating (TBC) topcoat materials with ultra-low thermal conductivities for next-generation gas turbine engines. A novel pyrochlore-based single-phased ceramic, tuned by codoping of lanthanum zirconate, (La1-xYx)2(Zr1-yCey)2O7, has been synthesized from the solid state reaction method. The thermal conductivity of (La1-xYx)2(Zr1-yCey)2O7 not only exhibits a temperature-independent trend but also reaches as low as 0.93 W·m−1·K−1, a value that is lowest of fully dense crystalline solids in open literature, attributing to the following two combined effects. The first is the strong scattering of phonons by small-sized Y3+ cations occupying the oversized atomic cages formed by the distinctive pyrochlore structure. The second is the lattice softening effects arising from larger-sized Ce4+ substituting Zr4+ cations. The above two effects act in concert and thus form a glasslike and ultra-low thermal conductivity of (La1-xYx)2(Zr1-yCey)2O7 solid solutions, which is ideal for next-generation TBC topcoat applications.
期刊介绍:
The Journal of the European Ceramic Society publishes the results of original research and reviews relating to ceramic materials. Papers of either an experimental or theoretical character will be welcomed on a fully international basis. The emphasis is on novel generic science concerning the relationships between processing, microstructure and properties of polycrystalline ceramics consolidated at high temperature. Papers may relate to any of the conventional categories of ceramic: structural, functional, traditional or composite. The central objective is to sustain a high standard of research quality by means of appropriate reviewing procedures.