MAGNETORESISTANCE IN FE-SI FILMS GROWN BY MOLECULAR-BEAM EPITAXY

We have used molecular beam epitaxy apparatus to grow Fe-Si films. The films were grown by first depositing a nominal 40 Angstrom of Fe, the n a nominal thickness of Si, then a further nominal 40 Angstrom of Fe. A plot of the ratio (remanent magnetisation/saturation magnetization) versus nominal Si layer thickness shows a minimum for a nominal thick ness of 25 Angstrom, and a plot of saturation field versus nominal Si thickness has a maximum for a nominal thickness of 20 Angstrom. We fin d a room temperature magnetoresistance of more than 2% in films with n ominal Si layer thicknesses of 20 Angstrom. Raising the temperature ca uses a decrease in (remanent magnetization/saturation magnetisation) f or films with nominal Si thicknesses of 20 Angstrom and 25 Angstrom.