NiFe epitaxial films are prepared on Cr(211)(bcc) and Cr(100)(bcc) underlayers grown hetero-epitaxially on MgO single-crystal substrates by ultra-high vacuum rf magnetron sputtering. The film growth behavior and the crystallographic properties are studied by reflection high energy electron diffraction and pole figure X-ray diffraction. Metastable hcp-NiFe(1 (1) over bar 00) and hcp-NiFe(11 (2) over bar0) crystals respectively nucleate on Cr(211)(bcc) and Cr(100)(bcc) underlayers, where the hcp-NiFe crystals are stabilized through hetero-epitaxial growth. The hcp-NiFe(1 (1) over bar 00) crystal is a single-crystal with the c-axis parallel to the substrate surface, whereas the hcp-NiFe (11 (2) over bar0) crystal is a bi-crystal with the respective c-axes lying in plane and perpendicular each other. With increasing the film thickness, the hcp structure in the NiFe films starts to transform into more stable fcc structure by atomic displacement parallel to the hcp(0001) close packed plane. The resulting films consist of hcp and fcc crystals. (C) 2011 Elsevier B.V. All rights reserved.