mgo303J. Magn. Soc. Jpn., 32, 296-303 (2008) Epitaxial Growth of Fe Thin Films on MgO Single-Crystal Substrates Kouhei Shikada, Kenji Tabuchi, Mitsuru Ohtake, Fumiyoshi Kirino*, and Masaakiare calculated from the lattice constants of the bulk MgO crystal (aMgO = 0.422 nm) [5], the bulk Py crystal (afcc–Py = 3.55 nm) [6] and from those of the hcp–Py film prepared in the present