Vacuum-Deposited Magnetic Thin Films of Fe3O4–B2O3 Mixtures

Publisher Website
Google Scholar
Abstract
Films of Fe3O4–B2O3, varying in starting compositions of 100% to 90% Fe3O4 mixed with 0% to 10% B2O3 proportionally by weight, were deposited from tungsten boats at a pressure of 2×10−5 Torr. It was found that the minimum B2O3 content was 5% for which films deposited from the mixture exhibited properties identifiable as those of magnetite. X‐ray and electron‐beam diffraction studies showed that films deposited from the 95–5 mixture and annealed in the vacuum to temperatures to 520°C were amorphous, but magnetite structure of increasing crystallinity was observed at higher annealing temperatures to 750°C. The optical reflection spectra of the annealed films in the 300‐ to 650‐mμ region agree with the bulk spectra. For films deposited at substrate temperatures less than 300°C, a low‐coercive magnetic switching dB/dt peak of 2.7 Oe was observed. A complex magnetic anisotropy was observed for the low coercive films. For films that were deposited and/or annealed at substrate temperatures greater than 300°C, the coercive fields were observed to be several orders of magnitude larger. The magnetic high coercivity has not been fully investigated.

This publication has 9 references indexed in Scilit: