We have attempted to grow single-crystalline Co4N thin films on SrTiO3 (STO)(001) substrates by molecular beam epitaxy by the simultaneous supply of 3N-Co and radio-frequency NH3 plasma. Reflection high-energy electron diffraction and theta-2 theta X-ray diffraction patterns confirmed that the epitaxial growth of Co4N films was successfully achieved. X-ray phi-scan measurements using Co4N(301) and STO(301) diffractions revealed that the epitaxial relationship between Co4N and STO was a cube-on-cube type. Magnetization versus magnetic field curves measured at room temperature for Co4N epitaxial layers covered with a Au capping layer using a vibrating sample magnetometer showed that Co4N[110] is the axis of easy magnetization. (C) 2011 Elsevier B.V. All rights reserved.