The (FeCo)(3)Pt thin films deposited onto MgO(1 0 0) and Al2O3(0 0 (.) 1) substrate are epitaxially grown with <1 0 0> and <1 1 1> orientation, respectively and exhibits large m-plane 4- and 6-fold magnetic anisotropy. The magnetooptical spectra of (FeCO)(3)Pt sample grown on the different substrates and different temperatures do not vary significantly and in both cases a negative Kerr rotation peak appears at nearly 5 eV. (C) 2004 Elsevier B.V. All rights reserved.