We present results for perpendicular uniaxial anisotropies obtained using torque magnetometry and magnetic force microscopy on epitaxially grown Co/Pt multilayers. A strong dependence of the two lowest order uniaxial anisotropies on Pt film thickness and temperature were observed. The possibility of an interfacial strain origin for the anisotropies due to lattice mismatch between the Co and Pt is discussed. A surprising result is the appearance of magnetic orientations at oblique angles with respect to the film plane and the surface normal. These orientations are identified as “cone states” and found to exist in limited ranges of Pt film thickness and temperatures. The temperature dependence is very unusual and controlled through the behavior of the lowest order perpendicular uniaxial anisotropies. The magnetization process was also examined in terms of saturation fields and domain formation. Narrow stripe domains with periods less than 100 nm were observed in the demagnetized state using magnetic force magnetometry and multilayer effects on the domain period and associated saturation fields were founds.

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Recent experiments in Co/CoO layered structures have shown a huge effect where the frequency of the lowest spin wave in the ferromagnetic Co has been doubled, apparently due to the interaction with antiferromagnetic CoO. We explore a microscopic model for spin waves in such coupled structures which can explain such an effect. In this model a magnetic material with a significant anisotropy is exchange coupled to a different magnetic material with minimal anisotropy. The shift in the spin-wave frequency increases as either the anisotropy or interface exchange is increased.

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Magnetic anisotropies of a 357-Å-thick Co film in the bcc phase were examined using Brillouin light scattering. This film, one of the thickest known bcc Co structures, is found to have a fourfold magnetic anisotropy that is markedly different from those of thinner films. A large possibly strain-induced uniaxial anisotropy is also found. The film is thick enough so that the surface and n=1 bulk magnon are within a few GHz of each other and strongly hybridize. Unusual behavior of the scattering intensities suggest the possible presence of surface anisotropies and/or inhomogeneous internal fields.