Fe/Cr/Fe sandwiches and (Fe/Cr)n, multilayers were prepared by ion beam sputtering on MgO(100) substrates by changing acceleration voltages. Lower acceleration voltage was crucial to obtain multilayers with high quality interfaces.Single crystalline Fe/Cr/Fe sandwiches were prepared with ambient substrate temperature having a relation of Fe(100)<110>//MgO(100)<lO0>.On the substrates with elevated temperature above 150°C,however,polycrystalline films were grown.Magnetic coupling between Fe-layers through intervening Cr layers was investigated by FMR using 9.4GHz,in which three resonance lines were observed for single crystalline Fe/Cr/Fe sandwiches and (Fe/Cr)n multilayers with antiferromagnetic Fe-layer interactions,while a single resonance line was observed for the polycrystalline films.Magnetoresistance measured on (20AFe/12ACr)5 single crystalline multilayers showed anisotropy in saturation fields Hs which are about 2 times lower in the applied field parallel to Fe<100> than to Fe<l10>,which is consistent with the magnetization process for the films.It was found that the shapes of the magnetoresistance curve vs magnetic field differ for H//Fe<100> and H//Fe<110>.