2Flux growth and characterization of Ce-substituted Nd2Fe14B single crystals

Abstract

Single crystals of (Nd1−xCex)2Fe14B are grown out of Fe-(Nd,Ce) flux. Chemical and structural analysis of the crystals indicates that (Nd1−xCex)2Fe14B forms a solid solution until at least x = 0.38 with a Vegard-like variation of the lattice constants with x. Refinements of single crystal neutron diffraction data indicate that Ce has a slight site preference (7:3) for the 4g rare earth site over the 4f site. Magnetization measurements show that for x = 0.38 the saturation magnetization at 400 K, a temperature important to applications, falls from 29.8 for the parent Nd2Fe14B to 27.6 µB/f.u., the anisotropy field decreases from 5.5 T to 4.7 T, and the Curie temperature decreases from 586 to 543 K. First principles calculations carried out within density functional theory are used to explain the decrease in magnetic properties due to Ce substitution. Though the presence of the lower-cost and more abundant Ce slightly affects these important magnetic characteristics, this decrease is not large enough to affect a multitude of applications. Ce-substituted Nd2Fe14B is therefore a potential high-performance permanent magnet material with substantially reduced Nd content.

Tuning the Magnetic Properties and Structural Stabilities of the 2-17-3 MagnetsSm2Fe17X3(Pandey1, Du2, Parker3 2018Phys. Rev. AppliedSelf Cite

“…Positive (negative) K corresponds to uniaxial (planar) anisotropy. Although the calculation of MAE from firstprinciples methods is somewhat difficult, as shown in some recent studies [22,[41][42][43][44][45] precise calculations often produce MAE in good agreement with experiments. To ensure the accuracy of MAE, its convergence with respect to number of k-point was carefully checked.…”

“…Materials based on RE and 3d-transition metals (TM) form a large family of permanent magnets with excellent properties, such as RE 2 Fe 14 B, RECo 5 , RE 2 Co 17 , and RE 2 Fe 17 C y compounds [9][10][11][12][13][14][15]. The notable example among these classes of RE compounds is Nd 2 Fe 14 B [16][17][18][19][20][21][22]. The discovery of Nd 2 Fe 14 B has also generated a lot of interest * This manuscript has been authored by UT-Battelle, LLC under Contract No.…”

Heat capacity, resistivity, and angular dependent magnetization studies of single crystal Nd1+∊Fe4BConner1, Susner2, Lampen-Kelley3 et al. 2017Journal of Magnetism and Magnetic Materials0000View full textAdd to dashboardCite

“…Single crystals of Nd 1+ Fe 4 B 4 were grown via flux growth as described previously [12]. Crystals as large as 0.5 × 0.5 × 1 cm 3 resulted with a, b, and c faces present that could be verified by x-ray diffraction (XRD) for orientation purposes.…”

Single-Crystal Permanent Magnets: Extraordinary Magnetic Behavior in theTa-,Cu-, andFe-SubstitutedLamichhane1, Onyszczak2, Palasyuk3 et al. 2019Phys. Rev. Applied

“…7 (f) is a high resolution STEM image taken from the matrix in Fig. 7 (d) under [1][2][3][4][5][6][7][8][9][10] zone axis. It is the same as that seen in Fig.…”

“…Despite the mixed Ce 3+ /Ce 4+ valency problem, typically adverse for the magneto-crystalline anisotropy, there are recent experimental efforts on the Nd 2 Fe 14 B (2:14:1) system showing that Ce-substitutes can compete with commercial high-flux grades at lower material costs. [4][5][6][7] Similarly, efforts on the Ce-containing SmCo 5 (1:5) and Sm 2 Co 17 (2:17) systems showed that satisfactory cost-toperformance balances suitable for modern rare earth criticalities and market demands are expected. [8][9][10][11] Therefore, we believe that Cu and Fe substituted CeCo 5 systems require a new and deeper examination.…”