Electrochemical Behaviour of the Rare Earth Neodymium

The rare earth metals are essential for highly energy-efficient technologies with many applications. The electrochemical behaviour, especially the material degradation by corrosion, is crucial for a long lifetime of electromagnetic devices. 

While the corrosion properties of some compounds containing these metals (e.g. NdFeB permanent magnets) have been characterized, the electrochemical behaviour of the pure metals is scarcely investigated. However, to understand the electrochemical behaviour of the alloys and compounds it is necessary to know the electrochemical behaviour of the pure elements. This will then allow developing corrosion protection strategies to ensure a low loss of efficiency during the lifetime of an electromagnetic device. Furthermore, the knowledge of the electrochemical behaviour of the rare earth metals opens the possibility to explore new low-cost recycling strategies of these materials.  

An electrochemical characterization of Neodymium in various aqueous electrolytes was performed. The corrosion properties and passive film formation as well as the local breakdown of passivity due to aggressive anions in the solution were investigated. Furthermore, an abnormal hydrogen evolution under anodic polarization conditions was observed.

R. Sueptitz, M. Uhlemann, A. Gebert, L. Schultz, Corrosion Science 52 (2010) 886