Transport Measurements of Magnetic Multilayers at Reduced Lateral Dimensions

Abstract

Abstract We report on the fabrication and transport properties of magnetic multilayers with widths down to 100 nm. We employ e-beam processed nano-deposition masks to pattern magnetic multilayers which define nano-wires by lift-off or by a removal process such as ion-milling. Two different magnetic multilayer systems (antiferromagnetically coupled Co/Cu multilayers and NiFe/Cu/Co spin-valves) are investigated. Structures resulting from the lift-off process show high contact resistance and high resistivities while ion-milled structures show resistivities close to that of bulk. For Fe(50Å)/[Co(15Å)/Cu(20Å)]x20 /Cu(30Å), patterned nano-wire structures display no negative magnetoresistance but a positive magnetoresistance that is linear with applied field and no apparent hysteresis. For Ta(50Å)/NiFe(50Å)/Cu(35Å)/Co(20Å)/Cu(30Å), we found the resistance to decrease as the absolute value of magnetic field is decreased and found hysteresis to be present.