[en] We report on the sputtering growth and characterization of nanostructures formed by a ferrimagnetic spinel (CoFe₂O₄) and a ferroelectric perovskite (BaTiO₃) on (0 0 1) and (1 1 1) oriented SrTiO₃ substrates. We present analysis of the crystal structure (crystal phases and lattice strain) and the surface morphology by X-ray diffractometry and by atomic force microscopy, respectively. Films grown on both substrates display phase segregation, being textured (either (0 0 1) or (1 1 1)) the films deposited at 700 deg. C and polycrystalline the ones grown at the highest deposition temperature (800 deg. C). The magnetic easy axis of films grown on SrTiO₃(0 0 1) is out-of-plane. It is found that phase separation and island size are depending on the growth conditions and the role of adatom supersaturation during growth is discussed