Magnetic Properties of Nano-Heterogeneous Amorphous Thin Films.

摘要

We report continued progress in understanding the nanostructuremagnetic property relationships in sputtered, amorphous, thin films. This research has been concentrated on two categories of sputtered magnetic thin films; (1) magnetically soft films, of cobalt-based, binary (cobalt-metalloid) alloys with in plane anisotropies, and (2) magnetically hard, binary (rare earth metal-transition metal) alloy films with perpendicular anisotropies. Major research results obtained include: (1) development of the first broadband measurement technique and apparatus for determining the complex permeability spectra of magnetic thin films in the 100KHz-200MHz frequency range; (2) processing of magnetically soft amorphous thin films with the highest values of RF permeabilities ever reported in the literature; (3) discovery of a new class of ultrasoft magnetic thin films with coercivities less than 0.1 Oe and completely reversible bias susceptibilities; (4) systematically studied the microstructure, magnetic and magneto-optic properties of Tb-Fe and Gd-Co compositionally modulated films; (4) demonstrated that substrate bias could be used to increase the oxidation resistance and improve the magnetic and magnetooptical properties of sputtered Tb-Fe CMFs; and (5) developed a model of displacement eddy currents to resolve a long standing mystery about the origin of eddy current losses in magnetic recording head laminates.