Electromagnetic levitation was used to melt and solidify containerlessly Nd–Fe–B alloys. A method was developed to reduce and evaporate stable solid Nd oxides at the surface of the liquid samples. The oxides otherwise limit the undercoolability of the highly reactive Nd-based alloys. In such a way, undercoolings up to 150 K of the levitation processed samples were achieved. Owing to the large undercooling range, the intermetallic Nd2Fe14B1 phase with the hard magnetic properties was primarily crystallized at undercoolings exceeding 50 K. Solidification of the pro-peritectic γ-Fe with soft magnetic properties was successfully suppressed. At the largest undercoolings, a metastable phase, likely to be of the composition Nd2Fe17Bx(x≈1) is primarily formed while the crystallization of Nd2Fe14B1 phase is followed up in a subsequent step.

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