The High-Pressure Characterization of Energetic Materials: Dihydrazinium 5, 5'-azotetrazolate dihydrate

The isothermal structural properties, equation of state, and vibrational dynamics of the high-nitrogen material Dihydrazinium 5, 5'-azotetrazolate dihydrate (HAT) were studied under high-pressure using synchrotron X-ray diffraction and optical Raman and Infrared microspectroscopy. At pressures near 4.5 GPa, X-ray diffraction characterization revealed an abrupt discontinuity in the compressibility, which when correlated with the mode splitting and intensity changes observed in the spectroscopic measurements, suggests the onset of a subtle isostructural phase transition. This paper will discuss the structural characteristics of the high pressure phase of HAT as well as its implications for the energetic properties of the material.