Tunnel-structured willemite Zn_(2)SiO_(4):Electronic structure,elastic,and thermal properties  

作　　者：Ruqiao DAI Renfei CHENG Jiemin WANG Chao ZHANG Cuiyu LI Hailong WANG Xiaohui WANG Yanchun ZHOU 

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China [3]Advanced Computing East China Sub-center,Suma Technology Company Limited,Kunshan 215300,China [4]School of Material Science and Engineering,Zhengzhou University,Zhengzhou 450001,China [5]Science and Technology on Advanced Functional Composite Laboratory,Aerospace Research Institute of Materials&Processing Technology,Beijing 100076,China

出　　处：《Journal of Advanced Ceramics》2022年第8期1249-1262,共14页先进陶瓷（英文）

基　　金：This work was supported by Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences.

摘　　要：Willemite Zn_(2)SiO_(4)crystallizes in such a way that Zn and Si are tetrahedrally coordinated with O in an ionic–covalent manner to form ZnO_(4)and SiO_(4)tetrahedra as the building units.The tetrahedra are corner-sharing,of which one SiO_(4)tetrahedron connects eight ZnO_(4)tetrahedra,and one ZnO_(4)tetrahedron links four ZnO_(4)tetrahedra and four SiO_(4)tetrahedra.The unique crystallographic configuration gives rise to parallel tunnels with a diameter of 5.7Åalong the c-axis direction.The tunnel structure of Zn_(2)SiO_(4)definitely correlates with its interesting elastic and thermal properties.On the one hand,the elastic modulus,coefficient of thermal expansion(CTE),and thermal conductivity are low.Zn_(2)SiO_(4)has low Vickers hardness of 6.6 GPa at 10 N and low thermal conductivity of 2.34 W/(m·K)at 1073 K.On the other hand,the elastic modulus and CTE along the c-axis are significantly larger than those along the a-and b-axes,showing obvious elastic and thermal expansion anisotropy.Specifically,the Young’s modulus along the z direction(Ez=179 GPa)is almost twice those in the x and y directions(Ex=Ey=93 GPa).The high thermal expansion anisotropy is ascribed to the empty tunnels along the c-axis,which are capable of more accommodating the thermal expansion along the a-and b-axes.The striking properties of Zn_(2)SiO_(4)in elastic modulus,hardness,CTE,and thermal conductivity make it much useful in various fields of ceramics,such as low thermal expansion,thermal insulation,and machining tools.

关 键 词：Zn_(2)SiO_(4) electronic structure elastic properties thermal expansion thermal conductivity 

分 类 号：TQ174[化学工程—陶瓷工业]