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A technique to sense the magnetic characteristics of the individual layers of a multi-layer structure is demonstrated. It detects the interaction between a thermal wave and the magnetization dependent thermal transport properties of the medium. A modulated laser beam is used to generate a thermal wave at the surface of a thin film sample and launch it into the medium. The amplitude and phase of the wave are modulated by the thermal properties of the medium as it propagates. Initial results for a AgNiFe magnetic thin film under a non-magnetic overlayer have successfully measured the magnetization dependent thermal conductivity. The measurements agree well with those obtained from the magnetization dependent resistivity.

The optical constants of a magnetic material may be determined by simultaneous measurement of the fractional changes in both the reflectance and the absorption introduced in the magneto-optic interaction when the sample magnetisation is reversed between saturated states. The magnetisation dependent photometric parameters, R and A, are determined without absolute measurement of optical intensity.

Magneto-optical measurements of the anisotropy of homogeneous [Dy.sub.18][Fe.sub.82], films as a function of thickness (134.0-13.4 nm) confirm that the perpendicular anisotropy disappears when films are less than 60nm thick. Since, the range of films exhibits both out of plane and in-plane anisotropy, both the polar Kerr effect and the transverse Kerr effect were used to determine the anisotropy. At about 60nm the perpendicular anisotropy [Mathematical Expression Omitted] the shape anisotropy ([K.sub.s]=2[Pi][[M.sub.s].sup.2]).

Comparison is made between the experimental and theoretical behaviour of the magneto-optical properties of a series of Co-Si[O.sub.2] films in which the volume fraction q occupied by the particles is varied between 0.4 and 0.8. A modified Maxwell Garnett model is used to compensate for both the surface oxidation of the cobalt particles and the reduced electron mean free path.

The magnetic and structural properties of Ba[Fe.sub.12][O.sub.19] films prepared by sputtering are compared with samples deposited using laser ablation deposition (LAD). Both techniques yield as-deposited films that are without crystal structure and consequently non-magnetic. The development of crystal structure and associated magnetic properties after rapid thermal processing (RTP [1]) and ultra-rapid thermal processing using a C[O.sub.2] laser is presented. Early results indicate that control of the oxygen content of the material is of critical importance during both preparation and subsequent processing. Provided this control is present a material with a significant perpendicular magnetic anisotropy can result from very rapid thermal processing.