A study of magnetic thin film corrosion mechanisms with the development of a novel on-line coupling technique and with microstructural and magnetic cross-sectional profiling techniques

This research develops a novel online analytical technique that couples electrochemistry (EC) with inductively coupled plasma mass spectrometry (ICP‑MS) to enable in‑situ, quantitative analysis of corrosion mechanisms in magnetic thin‑film structures. The system and methodology are demonstrated using multilayer magnetic thin films composed of CoCrPtB alloys and CrMo/Cr layers on Ni/P substrates. Results show that corrosion is dominated by elemental dissolution, with evidence of condition‑dependent passivation at micro‑ and macro‑scales. Microstructural analyses reveal that corrosion behavior is strongly influenced by grain orientation and grain boundaries. Changes in magnetic properties during corrosion are also observed, and kinetic models describing multilayer corrosion processes are proposed.