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Role of nitrogen on the atomistic structure of the intergranular film in silicon nitride: A molecular dynamics study

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Abstract

Molecular dynamics simulations of intergranular films (IGFs) containing Si, O, N, and Ca in contact with three different types of surface terminations of Si3N4 were performed using a multi-body interatomic potential. IGFs with the same Ca concentration (12 mol% CaO) but different nitrogen concentrations [N/(N + O) = 0, 15, 30, and 50%] were studied. In all 12 IGFs, Ca ions did not compete with the first adsorbed layer of Si at the IGF/basal crystal interface, but did so at the IGF/prism crystal interface. The simulations show the epitaxial adsorption of Si, O, and N from the IGF onto the basal and prism crystal surfaces. While more adsorbed N was expected as nitrogen concentration increases, there was a significantly larger amount of N adsorbed to the basal surface than to the prism surface. It was found that Ca ions sit closer to the prism surface than the basal surface but move closer to the crystal at both surfaces with increasing nitrogen concentration, although the effect was more pronounced at the basal interface. With the increase of nitrogen concentration, the percentage of two-coordinated oxygen remained about the same, but there was a change in the type of defect oxygen present. In all the simulations, the central position of the first peak in the Si-O pair distribution fixation (PDF) ranges from 1.63 to 1.65 Å, and that of Si-N PDF ranges from 1.71 to 1.73 Å, both consistent with experimental findings. Furthermore, the first peak of both the Si-O and Si-N PDF shifts to larger values as the nitrogen concentration increases, indicating the elongation of the Si-O and Si-N bond in the IGF with the increase of nitrogen concentration. Elongation of both the Si-N and Si-O bonds could lead to weakening of the IGF as nitrogen concentration increases, although competing changes in bonding of the O complicate the effect of N addition on the strength of the IGF.

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References

  1. F.F. Lange: Fabrication and properties of dense polyphase silicon nitride. Am. Ceram. Soc. Bull. 62, 1368 (1983).

    Google Scholar 

  2. R.L. Tsai and R. Raj: The role of grain boundary sliding in fracture of hot-pressed Si3N4 at high temperatures. J. Am. Ceram. Soc. 63, 513 (1980).

    Article  CAS  Google Scholar 

  3. R. Raj: Creep in polycrystalline aggregates by matter transport through a liquid phase. J. Geophys. Res. B 87, 4731 (1982).

    Article  CAS  Google Scholar 

  4. H-J. Kleebe: Structure and chemistry of interfaces in Si3N4 ceramics studied by transmission electron microscopy. J. Ceram. Soc. Jpn. 105, 453 (1997).

    Article  CAS  Google Scholar 

  5. J. Bruley, I. Tanaka, H-J. Kleebe, and M. Rühle: Chemistry of grain boundaries in calcia doped silicon nitride studied by spatially resolved electron energy-loss spectroscopy. Anal. Chimica Acta. 297, 97 (1994).

    Article  CAS  Google Scholar 

  6. H. Gu, X. Pan, R.M. Cannon, and M. Rühle: Dopant distribution in grain-boundary films in calcia-doped silicon nitride ceramics. J. Am. Ceram. Soc. 81, 3125 (1998).

    Article  CAS  Google Scholar 

  7. H. Gu, R.M. Cannon, and M. Rühle: Composition and chemical width of ultra-thin amorphous films at grain boundaries in silicon nitride. J. Mater. Res. 13, 376 (1998).

    Article  CAS  Google Scholar 

  8. H. Gu, R.M. Cannon, H.J. Seifert, M.J. Hoffmann, and I. Tanaka: Solubility of Si3N4 in Liquid SiO2. J. Am. Ceram. Soc. 85, 25 (2002).

    Article  CAS  Google Scholar 

  9. W-Y. Ching, S-D. Mo, and Y. Chen: Calculation of XANES/ ELNES spectra of all edges in Si3N4 and Si2N2O. J. Am. Ceram. Soc. 85, 11 (2002).

    Article  CAS  Google Scholar 

  10. M. Yoshiya, K. Tatsumi, I. Tanaka, and H. Adachi: Theoretical study on the chemistry of intergranular glassy film in Si3N4-SiO2 ceramics. J. Am. Ceram. Soc. 85, 109 (2002).

    Article  CAS  Google Scholar 

  11. G.S. Painter, P.F. Becher, and E.Y. Sun: Bond energetics at intergranular interfaces in alumina-doped silicon nitride. J. Am. Ceram. Soc. 85, 65 (2002).

    Article  CAS  Google Scholar 

  12. G. Pezzotti and G.S. Painter: Mechanisms of dopant induced changes in intergranular SiO2 viscosity in polycrystalline silicon nitride. J. Am. Ceram. Soc. 85, 91 (2002).

    Article  CAS  Google Scholar 

  13. S.H. Garofalini and W. Luo: Molecular dynamics simulations of calcium silicate intergranular films between silicon nitride crystals. J. Am. Ceram. Soc. 86, 1741 (2003).

    Article  CAS  Google Scholar 

  14. X. Su and S.H. Garofalini: Atomistic structure of calcium silicate intergranular films between prism and basal planes in silicon nitride: A molecular dynamics study. J. Mater. Res. 19, 752 (2004).

    Article  CAS  Google Scholar 

  15. J. Sjoberg, G. Helgesson, and I. Idrestedt: Refinement of the structure of Si2N2O. Acta Crystallogr. C47, 2438 (1991).

    Google Scholar 

  16. H. Berendsen, J. Postma, W. van Gunsteren, A. DiNola, and J. Haak: Molecular dynamics with coupling to an external bath. J. Chem. Phys. 81, 3684 (1984).

    Article  CAS  Google Scholar 

  17. S. Blonski and S.H. Garofalini: Molecular dynamics simulations of _-alumina and _-alumina surfaces. Surf. Sci. 295, 263 (1993).

    Article  CAS  Google Scholar 

  18. S. Blonski and S.H. Garofalini: Atomistic structure of calcium silicate intergranular films in alumina studied by molecular dynamics simulations. J. Am. Ceram. Soc. 80, 1997 (1997).

    Article  CAS  Google Scholar 

  19. W. McBride and D.J.H. Cockayne: The structure of nanovolumes of amorphous materials. J. Non-Cryst. Solids 318, 233 (2003).

    Article  CAS  Google Scholar 

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  1. Department of Ceramics and Materials Engineering, Rutgers University, Piscataway, New Jersey, 08854, USA

    Xiaotao Su & Stephen H. Garofalini

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  1. Xiaotao Su
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  2. Stephen H. Garofalini
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Su, X., Garofalini, S.H. Role of nitrogen on the atomistic structure of the intergranular film in silicon nitride: A molecular dynamics study. Journal of Materials Research 19, 3679–3687 (2004). https://doi.org/10.1557/JMR.2004.0471

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  • DOI: https://doi.org/10.1557/JMR.2004.0471

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