Speaker
Description
The extensive use of critical rare-earth elements like Nd and Sm in magnet production raises concerns about their limited availability [1]. Ongoing research explores the feasibility of cost-effective hard magnetic materials by substituting Nd or Sm with more abundant rare-earth elements such as Ce or La [2]. Here, it is crucial to deepen our understanding of the electronic and magnetic structures of compounds consisting of these low-cost rare-earth elements.
Here, we study the role of Ce as a candidate to replace heavy RE elements by investigating its 4f/5d valence state in different Ce-substituted permanent magnet systems. X-ray absorption spectroscopy was performed on Ce-Co, Ce-Co-Zn, and Ce-Co-Cu systems with varying compositions, examining the respective K, L$_{2,3}$, and M$_{4,5}$ edges of their components. We correlate the spectroscopically determined Ce valence with the composition and magnetic properties to understand the influence of Ce content on their magnetic properties.
We acknowledge the financial support of the German Research Foundation (CRC/TRR 270), the BMBF (05K2019 and 05K2022), Toyota Motor Corporation and the French National Research Agency (ANR-22-CE91-0008). Furthermore, we thank the ESRF for the allocation of beamtime at beamlines ID12 & ID32 within projects MA-5882 & MA-6819.
[1] O. Gutfleisch et al. Adv. Mater. 23, 821-842 (2011)
[2] K. P. Skokov et al. Scripta Materialia, 154, 289-294 (2018)
