Preparation and magnetic properties of EuO thin films epitaxially grown on MgO and SrTiO3 substrates

Ferromagnetic EuO films were epitaxially grown on MgO and SrTiO3 substrates aligned with EuO[100]//MgO[100], EuO(001)//MgO(001) and EuO[100]//SrTiO3[110], EuO(001)//SrTiO3(001). The single phase EuO film was obtained on MgO substrate, The higher order oxides, Eu2O3, was always present in the films on SrTiO3 substrate due Co the reaction of europium metal and grown EuO with oxygen in SrTiO3. The optimized flux ratio of oxygen to europium, J(OXY)/J(Eu), was 0.39, for J(Eu) = 2.83 x 10(13) cm(-2) . s(-1). The representative growth rate was 9.0 x 10(-2) Angstrom/s on MgO. Magnetic moment per europium atom was 6.9 +/- 0.3 mu(B). The Curie temperature was 69 K for films on MgO. The T-C higher than 69 K was observed for films on SrTiO3 thicker than 50 Angstrom. The thickness of 400 Angstrom was enough for the coercive field to be as low as 50 Oe.