Irreversible magnetization in isovalently doped Ba(Fe1-xRux)2As2

We report the superconducting properties of single-crystalline Ba(Fe1-xRux)2As2 by measuring its resistivity, upper critical field, magnetization, and magneto-optical images. Ba(Fe1-xRux)2As2 single crystal shows superconductivity at ∼ 20 K. The upper critical field determined by resistive transition is anisotropic with an anisotropy parameter of ∼ 2.2. The irreversible magnetization measurement shows a diminished but distinct fish-tail effect and a relatively high critical current density over Jc = 6 ¥ 105 A/cm2 at 2 K, slightly smaller than that in Co-doped BaFe2As2.