Crystal Growth of High-melting Multi-component Rare Earth-Transition Metal Intermetallic Compounds from the Melt

Abstract

The crystal growth of different classes of high melting multi‐component Rare Earth‐Transition Metal‐Compounds by vertical floating zone melting with inductive heating has been investigated. Phase diagram features of the multi‐component systems relevant for the crystallization process have been revealed. The critical zone travelling rate for RENi2B2C crystal growth is one order of magnitude smaller than for RE2TMSi3 compounds. This is attributed to different solidification modes of both classes of compounds, peritectic and congruent melting, respectively. The crystal perfection, element segregation and selected properties of the bulk crystals such as critical temperature of superconductivity were studied as function of the axis co‐ordinate. In the case of RE2TMSi2 plate‐like RESi or RESi2 precipitates were detected in the single crystalline matrix. They were partially dissolved by annealing and subsequent quenching. The anisotropy of various superconducting and magnetic properties was determined at YNi2B2C and TbNi2B2C single crystalline specimens.

Rare-earth metal transition metal borocarbide and nitridoborate superconductors

“…Single crystals of RNi 2 [B 2 C] with R ¼ Pr, Tb, Dy, and Ho few mm in size were grown by a cold crucible method using RF-heating [51]. Larger crystals of high quality (low widths of superconducting transition temperature and magnetic ordering temperatures, if applicable) with R ¼ Y, Pr, Tb, Ho and M ¼ Ni were grown by RF-zone melting from polycrystalline materials [38][39][40][52][53][54][55]. This technique was also suitable for crystals of solid solution phases with two different rare-earth metals [56].…”

“…A recent brief review gathers details on the floating zone growth of RNi 2 [B 2 C] compounds [57]. During these investigations pseudobinary sections of some phase diagrams R--Ni--B--C were determined [38,40,41,52] [62,63].…”

Crystal Growth of Magnetic Materials

“…Crystals grown by the Ni 2 B-flux method provide a basis for the determination of several anisotropic physical properties of quaternary RNi 2 B 2 C but suffer from the relatively small size and imperfections arising from the flux (Cho et al, 1995;Rathnayaha et al, 1997). For some of the compounds the FZ methods were applied for the growth of bulk crystals typically 6 mm in diameter and up to 40 mm in length (Takeya, Hirano and Kadowaki, 1996;Takeya, Kadowaki, Mirata and Mirano, 1996;Behr et al, 1999;Behr and Löser, 2005). The TbNi 2 B 2 C compound displays antiferromagnetic ordering below T N = 14 K. The relevant pseudobinary section TbB 2 C 2 -TbNi 2 B 2 C-TbNi 4 B of the quaternary phase diagram with a peritectic temperature of T p = 1518 • C is shown in Figure 30 (Behr et al, 1999).…”

Phase diagram studies on Er2PdSi3 and ErPd2Si2 intermetallic compounds

“…Even exotic phenomena such as magnetically mediated superconductivity in CePd 2 Si 2 are predicted [6]. In recent years single crystals both of RE 2 PdSi 3 [10][11][12][13][14][15] and CeTM 2 Si 2 compounds [16,17] were grown. They provided a basis for elucidating the sizeable anisotropy of the magnetic properties of RE 2 PdSi 3 compounds caused by the delicate balance of crystal-electric field and magnetic exchange interaction [9,10,[13][14][15].…”

“…Despite the large interest in crystal structure and physical properties of RE-Pd-Si intermetallic compounds there was a nearly complete lack of phase diagram data. Because of the reactivity of elements and high melting temperatures of the compounds ternary phase diagrams, Tb-Pd-Si [11], and Dy-Pd-Si [12], were studied only very recently in context with crystal growth experiments.…”