Crystal growth of Sr2RuO4

Abstract We describe the details of crystal growth of Sr 2 RuO 4 by a floating-zone method. The superconducting transition temperature T c can be controlled by adjustment of crystal growth conditions. By optimizing the growth conditions, crystals with T c up to 1.50 K have been obtained. In addition, we observed three kinds of two-phase composite structures grown under different conditions. They include (1) a Sr 2 RuO 4 –Ru eutectic system, in which lamellae of Ru are embedded in the primary phase of Sr 2 RuO 4 , resulting in a remarkable enhancement in T c by a factor of about 2; (2) epitaxial-like intergrowth of ferromagnetic SrRuO 3 on Sr 2 RuO 4 ; and (3) eutectic growth of Sr 2 RuO 4 and a new insulating phase with the possible composition of Sr 3 RuO 5+δ .