alpha-MnSe epilayers were grown on (100) GaAs substrates by hot-wall epitaxy and their structural characteristics were studied. X-ray diffraction (XRD) and double crystal rocking curve measurements revealed that the epilayer is a homogeneous layer of MnSe with a rocksalt structure in the (100) direction. Asymmetric XRD revealed that biaxial tensile strain remained in a 200 nm thick alpha-MnSe epilayer. (c) 2005 Elsevier B.V. All rights reserved.