PULSE PLATING OF HIGH MOMENT CoFe THIN FILMS

摘要

The electrodeposition of iron-rich, FeCo-based alloys was explored using current modulation techniques. By utilizing atomic-layer electrodeposition (ALE), shinny Fe_(65-70)Co_(30-35) films with 2.3 to 2.4-Tesla was obtained without any additives. The deposit has bcc structures with preferred orientations of (110) and little amounts of (211) planes. No (211) planes were observed in the films with B_s of 2.3 to 2.4-Tesla. Saturation moment of ALEed FeCo films can be controlled by iron contents, in agreement with Bozorth's diagram. Enhanced hydrogen evolution reaction (HER) associated with low-pH plating seems to facilitate monolayer deposition - a Hydrogen-assisted ALE mechanism being proposed. Film stress was found to be HER-related, regardless of iron contents. Stress build-up during ALE can be interrupted by laminating nano-oxide layers in the deposit through a conditional pulse reversal scheme. High throwing power was also observed with this novel approach.