Fe thin films were prepared on GaAs single-crystal substrates of (100)(B3), (110)(B3), and (111)(B3) orientations by ultra high vacuum rf magnetron sputtering. The effects of substrate orientation and substrate temperature on the film growth, the structure, and the magnetic properties were investigated. On GaAs(100)(B3) substrates, Fe (100)(bcc) single-crystal films are obtained at 300 degrees C, whereas Fe films consisting of bcc(100) and bcc(221) crystals epitaxially grow at room temperature (RT). Fe(110)(bcc) and Fe(111)(bcc) single-crystal films are respectively obtained on GaAs( 110)(B3) and GaAs(111)(B3) substrates at RT-300 degrees C. The in-plane lattice spacings of these Fe epitaxial films are 0-9% larger than the out-of-plane lattice spacings due to accommodation of lattice mismatch between the films and the substrates. The film strain is decreased by employing an elevated substrate temperature of 300 degrees C. The in-plane magnetization properties are reflecting the magnetocrystalline anisotropy of bulk bcc-Fe crystal. (C) 2011 Elsevier B.V. All rights reserved.