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, cilt.123, sa.43, ss.26095-26105, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 123 Sayı: 43
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1021/acs.jpcc.9b07658
  • Dergi Adı: Journal of Physical Chemistry C
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.26095-26105
  • Polis Akademisi Adresli: Evet

Özet

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.