Synthesis of Microwave Magnetic Materials as Oriented Sputtered Films

摘要

Significant results were made in the synthesis of ferrite films by bothsputtering methods and by pulsed laser ablation. An initial result of this program resulted in the nonepitaxial synthesis of strontium ferrite films with the crystallite c-axes aligned onto the substrate plane. For substrate temperatures near the comparatively low temperature of 500 deg C, the films consisted of random in-plane C-axes grains. ln later studies, nickel ferrite films with various textures were deposited onto different substrates by pulsed laser ablation. Nickel ferrite films deposited onto c-plane sapphire were single crystal films with a (111) orientation. Currently a pulsed laser deposition system is being purchased for installation at Queens College through a recently funded NSF ARI grant. In other parallel studies, SmCo based films exhibiting the TbCu7-type structure were synthesized and studied for a number of device type applications. SmCo based films with energy products of approximately 16 MGOe were synthesized for the biasing of permalloy films, YIG substrates, and in the fabrication of a film based Bi-YIG magneto-optical waveguide isolator. isolation ratios of 28-30 dB were obtained for light wavelengths from 1490-1555 nm.