Work

Partitioning of Tb and Dy at the liquid/Nd₂Fe₁₄B interface in Nd–Fe–B magnets: Insights from single crystal growth

Year: 2025

Type: article

Abstract: Heavy rare earth elements (HREE) such as dysprosium (Dy) and terbium (Tb) are added to Nd-Fe-B permanent magnets to increase their coercivity. However, optimizing both the content and distribution of HREE requires a thorough understanding of the thermodynamic equilibria at the interfaces between the τ 1 -phase grains and the liquid phase that forms during grain boundary diffusion or powder mixing processes. In this study, we synthesized τ 1 -phase single crystals using the flux growth method with Nd-HREE-Fe-B flux alloys containing various HREE concentrations. Following the crystal growth, phase separation was performed by centrifugation. The composition of the τ 1 single crystals was analyzed by wavelength dispersive spectroscopy (WDS), while the liquid phase was characterized by inductively coupled plasma (ICP) spectroscopy. The partitioning laws of HREE between the τ 1 phase and the equilibrium liquid phase were determined, providing valuable insights into the optimisation of HREE content in Nd-Fe-B magnets.

Source: Journal of Alloys and Compounds

DOI: 10.1016/j.jallcom.2025.185085

Authors: Raphaël Mouron, Cyril Rado, Eric Robin, Gérard Lapertot

Institutions: Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Laboratoire d’Innovation pour les Technologies des Énergies Nouvelles et les nanomatériaux, CEA Grenoble, Institut de Recherche Interdisciplinaire de Grenoble, Université Grenoble Alpes

Language: English

Topic: Magnetic Properties of Alloys

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,660

Funders: Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Centro de Ecológia Aplicada