Large osmium dioxide (OsO2)(1) single crystals with mirror-like prismatic facets have been successfully grown by the oscillating chemical vapor transport method. X-ray diffraction spectroscopy showed the tetragonal rutile structure and the lattice parameters were determined. The field emission energy dispersive X-ray analysis revealed the atomic ratio of Os to O to be about 1:2. The X-ray photoelectron spectra for both the Os 4f and O 1s core-level features exhibited strongly asymmetric line-shapes character. Temperature-dependent resistivity measurements indicated metallic character and a low room-temperature resistivity of similar to15 muOmega cm for the OsO2 single crystals. The residual resistivity ratio was determined to be 50. (C) 2003 Elsevier B.V. All rights reserved.