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

Volume

37

Issue

4

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

2079

Lastpage

2081

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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.951059

Filename

951059