High-Pressure Study of Two Polymorphs of 2,4,6-Trinitrotoluene Using Neutron Powder Diffraction and Density Functional Theory Methods


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Konar S., Michalchuk A. A. L., Sen N., Bull C. L., Morrison C. A., Pulham C. R.

Journal of Physical Chemistry C, vol.123, no.43, pp.26095-26105, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 123 Issue: 43
  • Publication Date: 2019
  • Doi Number: 10.1021/acs.jpcc.9b07658
  • Journal Name: Journal of Physical Chemistry C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.26095-26105
  • Police Academy Affiliated: Yes

Abstract

Copyright © 2019 American Chemical Society.A high-pressure neutron diffraction study was conducted on polycrystalline samples of the two known polymorphs of 2,4,6-trinitrotoluene [monoclinic (m) and orthorhombic (o) TNT] under hydrostatic conditions. Isothermal equations of state were obtained for both polymorphic forms. Neither polymorph was observed to undergo a phase transition in the pressure region 0-5 GPa, with both polymorphs displaying smooth compression behavior across the pressure range. This differs somewhat from previous X-ray diffraction and Raman spectroscopy investigations in which discontinuities were observed in the P-V curves and spectral changes were reported at â2 GPa. The high-pressure response of these materials is supported by dispersion-corrected density functional theory calculations which, while overestimating the experimental bulk moduli, give excellent agreement with the observed smooth compression response of both phases.