Electronic structure, mechanical properties and thermal conductivity of Ln2Zr2O7 (Ln =La, Pr, Nd, Sm, Eu and Gd) pyrochlore
The electronic structure,chemical bonding and mechanical properties of Ln2Zr2O7 (Ln =La,Pr,Nd,Sin,Eu and Gd) pyrochlore are investigated by local-density approximation of spin polarized scheme + U calculations (Uis the Hubbard energy) and further verifled by the experimental results.Ln2Zr2O7 compouods are wide band gap insulators,and this is consistent with the experiment results.The calculated spin polarized density of states of them indicates that they are in a ferromagnetic state and the magnetic moment is mainly attributed to the 4f shell of the Ln atoms.For the chemical bonds in the Ln2Zr2O7 crystals,the O-Zr bond is stronger than the O-Ln bond.The hardness,elastic constants,bulk modulus,shear modulus,Young's modulus and Poisson's ratio of Ln2Zr2O7 compounds are investigated and the theoretical values are in good agreement with the experiments.The mechanical anisotropic properties are discussed using Zener's indexes and universal elastic anisotropic index (AU).The sound velocities along [100],[110] and [111] directions are calculated for each Ln2Zr2O7 crystal.The thermal conductivities of Ln2Zr2O7 compounds are evaluated and the obtained thermal conductivity of Ln2Zr2O7 is lower than that of yttria-stabilized zirconia,indicating that they could be good low thermally conductive materials at high temperature.
Ceramics Coating Electronic structure Elastic behaviors First-principles electron theory
J.Feng B.Xiao C.L.Wan Z.X.Qu Z.C.Huang J.C.Chen R.Zhou W.Pan
State Key.Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engine Department of Physics, School of Science and Engineering, Tulane University, New Orleans, LA 70118, State Key.Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engine Key Laboratory of Advanced Materials of Precious-Nonferrous Metals.Education Ministry of China, Kunm
国际会议
南京
英文
207-225
2012-05-13（万方平台首次上网日期，不代表论文的发表时间）