Single Crystal Growth of the CeCu₂Si₂ Intermetallic Compound by a Vertical Floating Zone Method

Abstract

Large CeCu 2 Si 2 single crystals were grown by a vertical floating zone method with optical heating at slow zone traveling rates of 1-3 mm/h. Elevated Ar pressure of 3 MPa in the growth chamber was applied and floating zone was controlled by an in situ temperature measurement in order to minimize Cu evaporation. The compound exhibits incongruent melting behavior with Ce 2 CuSi 3 primary phase precipitates in the initial growth phase. Gradual accumulation of Cu in the floating zone finally led to the TSFZ growth mode of CeCu 2 Si 2 single crystals homogeneous over the whole cross section. The obtained CeCu 2 Si 2 crystal was proven to be single phase with no sign of Cu depletion in the final part, the X-ray single crystal diffraction study proved its excellent quality. It exhibited the S-type behavior with heavy fermion superconducting properties at T < T c = 0.58 K.

High-energy magnetic excitations from heavy quasiparticles in CeCu$_2$Si$_2$

“…Using inductively coupled plasma atomic-emission spectroscopy, we determined the atomic percentage of our samples to be Ce:20.1(1)%, Cu:40.3(1)% and Si:39.6(1)%. This stoichiometry is found to be consistent across several pieces of our samples, indicating they are dominantly S-type [63] in agreement with previous transport measurements [48]. Specific heat measurements were carried out for several pieces of our CeCu 2 Si 2 samples [Supplementary Fig.…”

“…Large single crystals of S-type CeCu 2 Si 2 with T c ≈ 0.5 K were grown using a vertical floating zone method [48]. Multiple crystals with a total mass of ≈ 12 g were co-aligned in the [H, H, L] scattering plane using the E3 fourcircle neutron diffractometer at the Chalk River Laboratory (see Methods section for details).…”

“…Several rod-shaped S-type CeCu 2 Si 2 single crystal samples were grown using a vertical optical heating floating zone method [Supplementary Fig. 4(a)] [48]. To avoid Si excess which results in A-type CeCu 2 Si 2 , we used a highpressure Ar atmosphere and a relatively small overheating of the floating zone beyond the melting temperature, which effectively reduces Cu evaporation.…”

Structures and physical properties ofR2TX3compounds

“…It is absolutely necessary to prepare larger-size single crystals with high quality and get more accurate information on the crystal structures, magnetic structures, and physical properties by neutron diffraction, synchrotron Xray scattering, and so on. Since the crystal growth techniques are drastically improved, [81][82][83] large single crystals with high perfection are expected to be grown and more unique phenomena will be revealed in the R 2 T X 3 compounds.…”

Recent Progress of Floating-Zone Techniques for Bulk Single-Crystal Growth

“…Since the successful growth of silicon in the middle of the last century [27,28], the floating-zone technique has been widely applied to various categories of materials: oxides [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45], chalcogenides [46][47][48][49], silicides [50][51][52][53][54][55], borides [56][57][58][59][60][61][62][63], carbides [64][65][66][67][68][69][70], and intermetallic alloys [71][72][73][74][75][76]…”