Pressure resolved crystal structure parameters of ammonium dinitramide investigated by means of X-ray diffraction

The thermal and long-term stability of energetic materials (EMs) is of particular importance and interest. Before they fulfill their intended tasks, EMs are stored under various conditions, sometimes for years. For safety reasons unintended ignition needs to be avoided and on the other hand their performance must be preserved. With the high-temperature and high-pressure chamber HPC 900 from Anton Paar it is possible to conduct in-situ X-ray diffraction measurements to analyze structural changes of EMs under various gases, temperatures and/ or pressures. With the oxidizer ammonium dinitramide, temperature and pressure resolved X-ray diffraction measurements under nitrogen atmosphere have been conducted, to analyze changes in the crystal parameters. Of special interest in the evaluation of the lattice parameters were the suspected instable area around 60 °C, changes in crystal domain size under pressure, and the melting ranges.