OPTICAL AND MAGNETOOPTICAL PROPERTIES OF TBFECO FILMS

The fundamental optical and megneto-optical constants of rare-earth-transition-metal (RE-TM) alloys in the form of TbFeCo thin films have been measured using spectroscopic ellipsometry. The films were produced using conventional dc-magnetron sputtering from composite targets and were deposited on thin glass substrates. A comprehensive set of ellipsometric measurements were performed on several thick (> 100 nm) films using radiation incident at both the air-film and film-substrate interfaces. For the purposes of confirming the reliability of the computed optical constants ellipsometric measurements were also carried out on films protected by a thin (approximately 15 nm) overlayer of silicon dioxide. Further verification of the usefulness of the computed constants was made by using them to predict the complex normal-incidence Kerr rotations and comparing these with actual values, measured using a normal-incidence Kerr-effect polarimeter.