Floating zone growth and carrier relaxation dynamics in single crystals of Sr2RuO4 near the clean limit

Abstract We report details of floating zone growth of Strontium ruthenate Sr 2 RuO 4 single crystals near the clean limit, with a high onset T c ∼1.5 K. We identify conditions under which pure and defective phases, such as the Ru-precipitate based 3K-phase, form. Electronic properties, X-ray diffraction, electron probe microscopy and superconducting properties help us tailor different growth parameters. We also report the first studies of carrier relaxation time in Sr 2 RuO 4 using optical pump–probe reflectivity measurements down to the femtosecond scale. We find a very long relaxation time at 8 K, indicating low disorder and weak carrier-lattice coupling at low temperatures.