Properties of films prepared from low surface area/density alumina-silica
A sol-gel method was use to prepare bulk, closed pore, amorphous alumina-silica. Films prepared from this 47wt% Al{sub 2}O{sub 3}- SiO{sub 2} composition were examined by SAW, elipsometry and electrical measurements. The films were found to have a surface area of 1.1 cm{sup 2}/cm{sup 2}, a refractive index of 1.44 at 633 nm, and a relative permittivity of 6.2 at 200 KHz. These properties indicate potential applications as hermetic seals, barrier coatings, dielectric layers for capacitors and passivation coatings for electronic circuits.