Experimental Study of the Crystal Habit of High Explosive Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in Acetone and Dimethyl Sulfoxide

Crystal morphology has a significant
effect on the properties and
applications of energetic materials (EMs). Here, we have combined
the single-crystal X-ray diffraction (SCXRD) and rotation imaging
techniques to study the crystal habit of high explosive octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine
(HMX) in different solvents. The Miller index and area of the exposed
facets have been determined for the HMX crystals grown in acetone
and dimethyl sulfoxide (DMSO). For the crystals grown in acetone,
the exposed facets have the morphology importance in the order of
(011) > (110) > (020) > (101̅), while for those grown
in DMSO
the order is (011) ≈ (110) > (020) > (101) > (101̅).
This indicates that DMSO can significantly decrease the growth rate
of the (110) and (101) planes of the HMX crystal compared to acetone,
which has not yet been reported. These results provide clear experimental
evidence for the evaluation of the crystal morphology prediction of
HMX by theoretical calculation and will be an important reference
to the morphology control of EMs.