Top and Bottom Spin Valves With Ni-Fe-Mn Antiferromagnetic Layer

Ilya Blinov,Tatiana Krinitsina,Vladimir Popov,Mikhail Milyaev,Vladimir Ustinov,N Perov,A Semisalova

doi:10.1051/epjconf/201818501006

Abstract

Structure, magnetic and magnetoresistive properties of spin valves with Ni-Fe-Mn antiferromagnet as a pinning layer have been studied. A technique of fabrication of spin valves with an enhanced thermal stability and improved hysteretic characteristics has been elaborated.

Highlights

Bilayers of permalloy/antiferromagnetic triple Ni-Fe-Mn alloy have been studied, as well as magnetic and magnetoresistive properties of spin valves (SVs) with Ni-Fe-Mn antiferromagnet (AF) as a pinning layer
The ordered AF phase formation is testified by an appearance of super-structural Debye rings (100), (110), (210), (211) in electron diffraction patterns of sample Al2O3/Mn(50 nm)/Ni77Fe23(30 nm)/Ta(5 nm) after its annealing in the magnetic field at Tann = 260 оС for 4 h
The magnetoresistance of the as-fabricated spin valve Al2O3/Ni-FeMn/Co90Fe10(5.5 nm)/Cu(3.6 nm)/Co90Fe10(5.5 nm)/Ta(5 nm) is ΔR/Rs = 3.8 % (Fig. 4). This value is significantly higher than the effect obtained in [1], since the replacement of permalloy in the free and pinning layer by Co or the Co90Fe10 alloy leads to an increase in spindependent scattering and an increase in the giant magnetic resistance effect (GMR) in the spin valves [7]

Summary

Introduction

Bilayers of permalloy/antiferromagnetic triple Ni-Fe-Mn alloy have been studied, as well as magnetic and magnetoresistive properties of spin valves (SVs) with Ni-Fe-Mn antiferromagnet (AF) as a pinning layer. To apply the ordered Ni-Fe-Mn AF phase in spin valves, a definite deposition order of permalloy and manganese layers is necessary. The permalloy layer should be deposited on manganese or the manganese containing alloy [1]. With this deposition order, the authors of [2] fixed the high value Hex = 110 Oe after the annealing of the FeMn(15nm)/NiFe(15nm) bilayers. The annealing of Ni48Fe12Mn40 and Ni32Fe8Mn60 films which after magnetron sputtering from the targets of corresponding compositions, were in the state of a homogeneous ternary solid solution did not result in the formation of an ordered antiferromagnetic phase. A similar result was found in [3]

Experimental details

Results and discussion

Conclusion