Journal of Inorganic Materials ›› 2011, Vol. 26 ›› Issue (2): 180-184.DOI: 10.3724/SP.J.1077.2011.00180

• Research Paper • Previous Articles     Next Articles

First-principlesStudy of Piezoelectricity of Si3N4 Crystal

ZENG Yi-Ming, ZHENG Yan-Qing, XIN Jun, KONG Hai-Kuan,CHEN Hui, TU Xiao-Niu, SHI Er-Wei   

  1. ShanghaiInstitute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, China
  • Received:2010-04-28 Revised:2010-09-01 Published:2011-02-20 Online:2011-01-21
  • Supported by:

    National Nature Science Foundation of China (50772121); Knowledge Innovation Program of China Academy of Sciences (KGCX-2-YW-206)

Abstract: Si3N4 is apopular material with many excellent physicochemical properties. This presentwork make a comparative study on its low and high temperature phases (α- and β-Si3N4)by first-principles calculation based on density functional theory (DFT). Asfor α phase, the calculated lattice parameters are <>a=0.7678nm, <>c=0.5566nm;elastic- stiffness coefficients are c11=4.232×1011N/m2, c33=4.615×1011N/m2; piezoelectric strain coefficients are <>d33=0.402pC/N. While for β phase, they area=0.7536nm, c = 0.2874nm, c11=4.241×1011N/m2, c33=5.599×1011N/m2 and the piezoelectric strain coefficients are nearlyzero. The analysis shows that both α and β phases are high strength and highhardness, relating to their network structures of tetrahedron. Thepiezoelectricity is poor, especially for β-Si3N4. Thiscan be attributed to the structural symmetry, higher symmetry and lowerpiezoelectricity.

Key words: Si3N4, piezoelectricity, first-principles, crystal structure

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