Bulk modulus and Young's modulus of nanocrystalline [gamma]-alumina

Compression measurements were performed for the first time on nanocrystalline [gamma]-alumina utilizing a diamond anvil cell (DAC) and the energy dispersive X-ray diffraction method. The cubic unit cell (a = 0.7924 nm) for [gamma]-alumina was found to have a volume compression of about 2.4% over the pressure range from ambient to 3.9 GPa at room temperature under both hydrostatic and nonhydrostatic conditions. Using the first-order Bridgman equation and another equation of state, the isothermal bulk modulus (B[sub 0]) was determined to be 162 [+-] 14 GPa and Young's modulus (E) was estimated to be 253 [+-] 22 GPa assuming a Poisson's ratio for [gamma]-alumina of 0.24 [+-] 0.2.