Anelastic compression of nanometer-sized silica particles under high pressure: A high-energy x-ray diffraction measurement

We compressed nanometer-sized silica particles, fumed silica, using a cubic-anvil-type apparatus up to pressures of 8 GPa at room temperature. The high-energy (61.7 keV) x-ray diffraction measurements of the recovered samples were carried out to determine the x-ray structure factor and in the real space correlation functions. These results indicate that anelastic compression occurs in silica nanoparticles in the pressure range from 4 to 8 GPa, which is well below the pressure regime of the anelastic compression ({~}10 to {~}20 GPa) observed for bulk amorphous silica.