Sm-Co Thick Films Micromolding

Abstract

This paper presents a study of the scale effect occurring during electrodeposition in the (micro)molding process of a rare earthtransition metal alloy : SmCo. Different cathode sizes have been implemented in the electrodeposition set up: a large strip (10 cm x 1.5 cm), a matrix of 1 mm² square and matrix of 5 -50 µm micropatterns. Results concerning composition, deposition rate, adherence and thickness uniformity of the patterns show an influence of the scale effect: the decreasing of the conductive surface of the cathode leads to thinner films containing less samarium, but also a lower oxygen content. Patterns are then free of cracks, more uniform in thickness and present a good adherence to the copper seed layer. The influence of the deposition time has been also studied for micromoulding process, showing an increase of the samarium content but a decrease of the deposition rate during the deposition.

Shape Anisotropy in Magneto-Impedance NiFe-Based Microsensors

“…However, the measurement involves the applied magnetic field, thus the potential demagnetizing effect due to the planar geometry. Actually, such demagnetizing effect has been already observed on thick NiFe micromolded square patterns (19), leading to a decreasing of the effective permeability while the thickness/size ratio of the pattern increases. This can be modelized by a demagnetizing factor proportional to the thickness/size ratio and explain also the increasing transverse anisotropy field when thickness increases or width decreases.…”