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Theoretical Prediction of Elastic Stiffness and Minimum Lattice Thermal Conductivity of Y 3 Al 5 O 12 , YAlO 3 and Y 4 Al 2 O 9
Author(s) -
Zhan Xun,
Li Zhen,
Liu Bin,
Wang Jingyang,
Zhou Yanchun,
Hu Zijun
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2012.05118.x
Subject(s) - ternary operation , phonon , thermal conductivity , lattice (music) , thermal , crystal structure , materials science , analytical chemistry (journal) , chemistry , crystallography , mineralogy , thermodynamics , composite material , condensed matter physics , physics , chromatography , computer science , acoustics , programming language
Combining C larke's model with first‐principles calculation of average sound velocity, the minimum lattice thermal conductivities ( κ min ) of Y 3 Al 5 O 12 ( YAG ), YAlO 3 ( YAP ) and Y 4 Al 2 O 9 ( YAM ) are predicted to be 1.59, 1.61, and 1.10 W·(m·K) −1 , respectively. The weak Y – O polyhedra provide “weak zones” that scattering phonons and lead to the low κ min of ternary Y – Al – O compounds. In addition, the extremely low κ min of YAM is attributed to its higher levels of local disorder of crystal structure and weaker chemical bonding compared with those of YAG and YAP . Inspired by theoretical predictions, dense and phase‐pure YAM is synthesized and the experimental thermal conductivity is only 1.56 W·(m·K) −1 at 1273 K. Finally, YAM is highlighted as a potential thermal barrier material for its low thermal conductivities at temperatures from 473 to 1273 K.