Fabrication and magnetic properties of Al2O3/Co nanocomposites

Al2O3/Co nanocomposites were synthesized by dispersing submicron-sized cobalt particles into Al2O3 matrix via vacuum hot-pressing technique. The size of cobalt particles increased with increasing cobalt content, and the growth as well as coalescence of cobalt particles occurred at 50 wt.% Co addition. The phases formed in the Al2O3/Co composites were f-Co(fcc), h-Co(hcp), α-Al2O3, and a small amount of C. Ferromagnetic properties with high mechanical properties were achieved simultaneously by incorporating submicron-sized cobalt particles into the Al2O3 matrix.