Single crystals of superconducting SmFeAsO1−xFy grown at high pressure

Single crystals of SmFeAsO1−xFy of a size up to 120 × 100 μm2 have been grown from NaCl/KCl flux at a pressure of 30 kbar and temperature of 1350–1450 ◦C using the cubic anvil high-pressure technique. The superconducting transition temperature of the obtained single crystals varies between 45 and 53 K. Obtained crystals are characterized by a full diamagnetic response in low magnetic fields and by a high critical current density in high magnetic fields. Structural refinement has been performed on the single crystal. Differential thermal analysis investigations at 1 bar Ar pressure show decomposition of SmFeAsO1−x Fy at 1302 ◦C. (Some figures in this article are in colour only in the electronic version)