We have investigated the magnetization reversal processes in arrays of sub-micron Ni and Co wires by means of magnetization and torque experiments together with micromagnetic calculations. The wires were produced by electrodeposition in the cylindrical pores of track-etched polymer membranes. Diameters in the range 35–400 nm have been studied. The arrays of Co and Ni nanowires display different magnetic behaviors. Particular emphasis is given to the competing shape and crystal magnetic anisotropies that exist in the Co nanowire system. In both systems, explaining the experimental results requires domain formation, except for the smallest diameters where single domain behavior occurs.

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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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