Magnetic thin films produced by sol-gel processes

Abstract

Iron oxide films on borosilicate glasses were produced with the sol-gel method. The ESR spectra of the as-produced films exhibit two signals, one at g about 4.2 and the other at g about 2. A ferromagnetic signal was detected by heat-treating the samples in hydrogen atmosphere between 500 and 800 °C. Angular variation of the ferromagnetic resonance signals revealed an internal field parallel to the plane of the films. The internal field was about 3500 G in the film heat treated at 620 °C for 120 min. Scanning electron microscopy was also used for detailed surface characterization. Before treatments the film is characterized by a fine texture and a few voids whose dimensions are about 5×15 μ. After treatments the film contains particles about 15 μ in size.