Growth and characterisation of CeCu sub 2 Si sub 2 single crystals

The heavy fermion superconductor CeCu sub 2 Si sub 2 shows interesting low temperature properties and a complex B-T phase diagram. Crystal growth is complicated due to the high vapour pressure of Cu and Si at the melting point (about 1540 deg C), the peritectic melting behaviour and a lack of crucible materials. We have grown single crystals of CeCu sub 2 Si sub 2 from a levitated melt using the Nacken Kyropoulos technique. We present ultrasonic measurements, which show the low temperature properties of different CeCu sub 2 Si sub 2 single crystals.