Title :
Control of the switching properties of magnetic thin films and spin valve devices by patterning
Author :
Morecroft, D. ; Leung, C.W. ; Stelmashenko, N.A. ; Prieto, J.L. ; Jardine, D.B. ; Blamire, M.G.
Author_Institution :
Dept. of Mater. Sci., Cambridge Univ., UK
fDate :
7/1/2001 12:00:00 AM
Abstract :
The effects of patterning highly anisotropic repeating structures in soft magnetic thin films have been examined. Arrays of wires with equal mark/space ratios were patterned in resist using optical lithography. 100 nm thick Ni80Fe15Mo5 films were partially or completely etched using broad beam ion milling to assess the dependence of magnetic properties on the degree of interconnection between the wires. These structures show a progressive increase in coercivity and a transition between single and two-stage switching with increasing milling depth. A similar nanopatterning technique has been applied to unpinned (Ni80Fe20/Cu/Ni80Fe20) spin valve structures in order to enhance the coercivity of one of the ferromagnetic layers; the increased coercivity induced by patterning changes the natural similarity of the magnetic layers and the completed structure exhibits a small spin valve response
Keywords :
coercive force; copper; etching; ferromagnetic materials; iron alloys; magnetic multilayers; magnetic switching; magnetic thin films; molybdenum alloys; nickel alloys; photoresists; soft magnetic materials; spin valves; Cu; Ni80Fe15Mo5; Ni80Fe15Mo5 films; Ni80Fe20; broad beam ion milling; coercivity; ferromagnetic layers; highly anisotropic repeating structures; interconnection; magnetic properties; milling depth; nanopatterning technique; optical lithography; patterning; resist; soft magnetic thin films; spin valve devices; switching properties; unpinned Ni80Fe20/Cu/Ni80Fe20 spin valve structures; wire arrays; Coercive force; Iron; Magnetic films; Magnetic properties; Magnetic switching; Milling; Optical arrays; Optical films; Spin valves; Wires;
Journal_Title :
Magnetics, IEEE Transactions on
