Physical Properties of Single-Crystalline CaRuO₃ Grown by a Floating-Zone Method

We report the successful growth of single crystals of the perovskite ruthenate CaRuO3 by a floating-zone method, and characterization of their physical properties by x-ray diffraction, electrical resistivity, magnetic susceptibility, and specific heat. Although the system is strongly correlated, with an electronic specific heat coefficient of approximately 80 mJ/(mol K-2 Ru), the physical properties are nearly isotropic, reflecting the almost cubic crystal structure. No obvious phase transitions are observed down to 0.12 K, in contrast to observations on other metallic ruthenates with the Ruddlesden-Popper type layered perovskite structure A(n+1)Ru(n)O(3n+1) such as Sr2RuO4, Sr3Ru2O7, and Ca3Ru2O7.