Magnetic and magnetoresistive properties of epitaxial Co/Cu/Co trilayers on Si(111)

► We study growth and magnetoresistance of epitaxial Co/Cu/Co(111) trilayers on Si(111). ► The first maximum of giant magnetoresistance is detected at 3.0 ML coverage of Cu spacer. ► The portion of antiferromagnetic coupling in the first antiferromagnetic maximum is 17%. ► 3D growth of Cu spacer is observed that leads to lack of antiferromagnetic coupling.