Rare earth–copper–magnesium compounds RECu9Mg2 (RE=Y, La–Nd, Sm–Ho, Yb) with ordered CeNi3-type structure

✍ Scribed by P. Solokha; V. Pavlyuk; A. Saccone; S. De Negri; W. Prochwicz; B. Marciniak; E. Różycka-Sokołowska

• Book ID: 104029654
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 488 KB
• Volume: 179
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2006.05.040

✦ Synopsis

A series of ternary compounds RECu 9 Mg 2 (RE ¼ Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb) have been synthesized via induction melting of elemental metal ingots followed by annealing at 400 1C for 4 weeks. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDXS) was used for examining microstructure and phase composition. These phases crystallize with an ordered version of the binary hexagonal structure type first reported for CeNi 3 . The crystal structure was solved for TbCu 9 Mg 2 from single crystal X-ray counter data (TbCu 9 Mg 2 -structure type, P6 3 /mmc-space group, hP24-Pearson symbol, a ¼ 0.49886 (7) nm, c ¼ 1.61646 (3) nm, R F ¼ 0.0474 for 190 unique reflections). The Rietveld refinement of the X-ray powder diffraction patterns of RECu 9 Mg 2 confirmed the same crystal structure for the reported rare earth metals. The unit cell volumes for RECu 9 Mg 2 smoothly follow the lanthanide contraction. The existence of a RECu 9 Mg 2 phase was excluded for RE ¼ Er and Tm under the investigated experimental conditions.