Magnetic switching in 100 nm patterned pseudo spin valves

Author

Castaño, F.J. ; Hao, Y. ; Haratani, S. ; Ross, C.A. ; Vögeli, B. ; Walsh, M. ; Smith, Henry I.

Author_Institution

Dept. of Mater. Sci. & Eng., MIT, Cambridge, MA, USA

Volume

37

Issue

4

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

2073

Lastpage

2075

Abstract

Progress in developing operative high-density magnetoresistive random access memory (MRAM) devices relies critically on tailoring the magnetic switching occurring in arrays of small patterned pseudo spin valve (PSV) elements. Co/Cu/NiFe PSV films, produced by sputtering in the presence of a magnetic field, have an in-plane anisotropy and switching fields of typically 10 Oe for the soft NiFe and 40 Oe for the hard Co. These films were patterned into arrays of elliptical and circular elements with dimensions of 80 nm to 10 μm. The layered structure in these large-area arrays of compositionally modulated PSV elements is preserved through the patterning processes. Hysteresis measurements of the dot arrays show that the switching field of the hard layer increases significantly with decreasing element size, reaching 600 Oe for the smallest elements. Additionally, in patterned elements the soft layer switches prior to field reversal due to magnetostatic coupling between the layers, leading to antiparallel alignment at remanence

Keywords

arrays; cobalt; copper; iron alloys; magnetic anisotropy; magnetic hysteresis; magnetic multilayers; magnetic switching; nickel alloys; remanence; spin valves; sputtered coatings; 100 nm; Co; Co/Cu/NiFe PSV films; Cu; NiFe; antiparallel alignment; arrays; circular elements; compositionally modulated PSV elements; dot arrays; elliptical elements; high-density magnetoresistive random access memory devices; hysteresis; in-plane anisotropy; layered structure; magnetic switching; magnetostatic coupling; patterned elements; patterned pseudo spin valves; remanence; sputtering; switching fields; Magnetic field measurement; Magnetic fields; Magnetic films; Magnetic hysteresis; Magnetic switching; Magnetoresistance; Random access memory; Size measurement; Spin valves; Sputtering;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.951057

Filename

951057