TEM Study on Stability of Mg-Doped γ-Alumina Fine Particles

Ultrafine spherical particles of γ-Al 2 O 3 containing 4 at% magnesium and pure γ-Al 2 O 3 were prepared by evaporating metal Al in air. Consequently, both particles were heated at 1400°C for 6 h in a vacuum. TEM observations showed that the Mg-doped γ-Al 2 O 3 particles were much more stable than the pure γ-Al 2 O 3 particles. The role of Mg atoms on the stability is discussed mainly based on the results obtained by high-resolution electron microscopy and energy dispersive X-ray spectroscopy.