Electrodeposited Cylindrical Magnetic Films

Abstract

The magnetic characteristics of cylindrical electroplated films are considered. Pertinent previous work is reviewed and new data are presented which elucidate the following items: (a) Preparation. The influence of surface roughness is emphasized, and important recent work on surface topology is reviewed. (b) Magnetic Characterization. The use of susceptibility measurements to determine the anisotropy and the ripple amplitude are discussed. When the ripple amplitude is large, previous calculations of the susceptibility based on the linear ripple theory do not apply. Nevertheless, it is possible to use the susceptibility to characterize the anisotropy and dispersion if the susceptibility is described in terms of a phenomenological ripple field picture. (c) Domain Wall Creeping. The possible causes of creep in thick films are considered. From the thickness dependence of the creep threshold, it does not appear that the Olson-Torok model is adequate. Data on the creep velocity are presented. Finally, a model for creep is described which hinges on the distribution of wall motion fields along the wall. (d) Thermal Stabilization. It is shown that by annealing at elevated temperatures, adequate thermal stabilization of plated films can be achieved.

Magneto-impedance effect in NiFe plated wire

“…͑To obtain good fits, it was necessary to add an external, H Z independent, inductance of Ϸ5 nH, to account for the external inductance of the wire.͒ Similar behavior in plated wires has previously been observed. 11 Ironically, the accepted term ''magnetoimpedance'' does not truly describe the effect observed here for small H z , since V Z does not scale linearly with I 0 . V Z is also independent of the wire or magnetic film resistivity and, hence, is not due to the skin effect.…”

The effect of surface roughness on the susceptibility of thin permalloy films

“…Similar work has been carried out independently by Doyle et al (1969) on films electrodeposited on wires. Their work is in close agreement with ours and emphasizes the conclusion that the effect of surface roughness on the film properties is to increase the dispersion and produce the deviations in the susceptibility as outlined above.…”