Shock synthesis of nanocrystalline La₂Ti₂O₇ powder

Perovskite La₂Ti₂O₇ nanocrystalline powder was obtained through the shock synthesis method. In the study, La₂O₃ and TiO₂ powders were mixed through ball milling and, subsequently, shocked by a flyer at a velocity of 3.2 km/s. After shock treatment, the sample was recovered and characterized via various techniques, such as x-ray diffraction, Raman, scanning electron microscope, transmission electron microscope, and ultraviolet-visible diffuse reflection spectrum analysis, to find the presence of La₂Ti₂O₇ nanocrystalline powder with an average grain size of approximately 30 nm in the recovered samples with different yields. Moreover, the results further confirm that the high shock temperature and long ball milling treatment induce higher activation of precursors to improve the La₂Ti₂O₇ content in the recovered samples. By adjusting the relative density of precursor and the ball milling period, pure La₂Ti₂O₇ nanocrystalline powder was obtained. The formation mechanism of La₂Ti₂O₇ was carefully illustrated. This study presents a new method to synthesize La₂Ti₂O₇ nanocrystalline powder by detonation-driven flyer impact.