Oscillatory interlayer coupling and giant magnetoresistance in epitaxial Fe/Cr(211) and (100) superlattices

1993 ◽  
Vol 48 (21) ◽  
pp. 15755-15763 ◽  
Author(s):  
Eric E. Fullerton ◽  
M. J. Conover ◽  
J. E. Mattson ◽  
C. H. Sowers ◽  
S. D. Bader
Keyword(s):  
Giant Magnetoresistance ◽  
Interlayer Coupling

Giant magnetoresistance and interlayer coupling in Cu(111)/Ag67Co33 granular multilayers

1997 ◽  
Vol 81 (8) ◽  
pp. 4589-4591 ◽  
Author(s):  
Yuansu Luo ◽  
Michael Moske ◽  
Andrea Kaeufler ◽  
Tilmann Lorenz ◽  
Konrad Samwer
Keyword(s):  
Giant Magnetoresistance ◽  
Interlayer Coupling

Insertion of a Specular Reflective and Transmissive Nano-Oxide Layer into Giant Magnetoresistance Spin-Valve Structure

2006 ◽  
Vol 6 (11) ◽  
pp. 3483-3486
Author(s):  
Chunghee Nam ◽  
Youngman Jang ◽  
Ki-Su Lee ◽  
Jungjin Shim ◽  
B. K. Cho
Keyword(s):  
Oxide Layer ◽  
Sheet Resistance ◽  
Giant Magnetoresistance ◽  
Spin Valve ◽  
Interlayer Coupling ◽  
Free Layer ◽  
Uniform Layer ◽  
Nano Oxide ◽  
Valve Structure ◽  
Current Shunt

We have studied the influence of the insertion of a nano-oxide layer (NOL) into a magnetic GMR spin-valve. It was found that the spin-valve with NOL has a higher GMR ratio than that of the normal spin-valve without NOL. Naturally formed NOL without vacuum break shows a uniform layer, which effectively suppresses the current shunt, resulting in the reduction of the sheet resistance of GMR. The NOL spin-valve also shows a lower interlayer coupling (Hin) than that of the optimal normal spin-valve, which is consistent with AFM measurement showing lower roughness of NOL formed CoFe surface. Based on the advantage of NOL, we succeeded in lowering Hin while maintaining GMR ratio by insertion of NOL inside the CoFe free layer, where the free layer consists of CoFe/NOL/CoFe/NOL/Capping layer.

scholarly journals Orthogonal interlayer coupling in an all-antiferromagnetic junction

2021 ◽  
Author(s):  
Yongjian Zhou ◽  
Liyang Liao ◽  
Tingwen Guo ◽  
Hua Bai ◽  
Mingkun Zhao ◽  
...  
Keyword(s):  
High Speed ◽  
Giant Magnetoresistance ◽  
Spin Dynamics ◽  
Magnetic Ordering ◽  
Functional Materials ◽  
Interlayer Coupling ◽  
Information Storage ◽  
Stray Field ◽  
Potential Candidate ◽  
Ultrahigh Density

Abstract The interlayer coupling of two ferromagnetic layers results in found of giant magnetoresistance, which forms the foundation of spintronics and accelerates the development of information technology. Compared with ferromagnets, antiferromagnets (AFMs) possess huge potential in ultrafast and high-density data processing and information storage because of their terahertz spin dynamics and subtle stray field. The interlayer coupling in AFMs has long been neglected, because the collinear parallel and antiparallel arrangements of AFMs are indistinguishable. However, the noncollinear interlayer coupling in AFMs is detectable, and can be a potential candidate for practical antiferromagnetic spintronic devices. Here we demonstrate orthogonal interlayer coupling at room temperature in an all-antiferromagnetic junction Fe2O3/Cr2O3/Fe2O3, where the Néel vectors in the top and bottom functional materials Fe2O3 are strongly orthogonally coupled and the coupling strength of which is significantly affected by the thickness of the antiferromagnetic Cr2O3 spacer. From the energy and symmetry analysis, the direct coupling via uniform magnetic ordering is excluded. The coupling is proposed to be mediated by quasi-long range order in the spacer. Besides the fundamental significance, the strong coupling in an antiferromagnetic junction makes it a promising building block for practical antiferromagnetic spintronics with high-speed operation and ultrahigh-density integration.

Oscillatory interlayer coupling and giant magnetoresistance in Co/Cu multilayers

1991 ◽  
Vol 94 (1-2) ◽  
pp. L1-L5 ◽  
Author(s):  
D.H. Mosca ◽  
F. Petroff ◽  
A. Fert ◽  
P.A. Schroeder ◽  
W.P. Pratt ◽  
...  
Keyword(s):  
Giant Magnetoresistance ◽  
Interlayer Coupling

Effect of Ion Irradiation on the Artificial Structure and the Interlayer Coupling of Copper-Cobalt Multilayers

1994 ◽  
Vol 343 ◽  
Author(s):  
J-F. Bobo ◽  
E. Snoeck ◽  
M. Piecuch ◽  
M-J. Casanove
Keyword(s):  
Point Defects ◽  
Giant Magnetoresistance ◽  
Ion Irradiation ◽  
Interlayer Coupling ◽  
Structural Defects ◽  
Cross Sectional ◽  
Saturation Field ◽  
Artificial Structure ◽  
Short Circuits

ABSTRACTStructural defects like local ferromagnetic short-circuits are responsible for large reductions of the intrinsic interlayer coupling in the case of antiferromagnetically (AF) coupled multilayers (ML). We have investigated the role of such point defects in AF-coupled Cu-Co ML’s with tCu=8Å and tCo=12Å which have been irradiated with various doses of 200 keV xenon ions. A significant decrease of the giant magnetoresistance and of the saturation field is observed when the density of defects is increased. These results are compared with a micromagnetic model that takes into account local discontinuities of the AF coupling in an ideally AF-coupled ML. Evidence for the presence of such defects is investigated by TEM on cross-sectional specimens.

Superlattice Nanowires

1995 ◽  
Vol 384 ◽  
Author(s):  
K. Attenborough ◽  
R. Hart ◽  
W. Schwarzacher ◽  
J-PH. Ansermet ◽  
A. Blondel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Giant Magnetoresistance ◽  
Layer Structure ◽  
Interlayer Coupling ◽  
Nanoporous Membranes ◽  
Transmission Electron ◽  
Plane Anisotropy ◽  
Nonmagnetic Layer ◽  
Magnetostatic Coupling

ABSTRACTCoNiCu/Cu superlattice nanowires have been grown by electrodeposition in nuclear tracketched nanoporous membranes. Transmission electron microscopy (TEM) images show a good layer structure and allow an estimate of the current efficiency. Current perpendicular to plane (CPP) giant magnetoresistance of up to 22%, at ambient temperature, has been measured but appears to be limited by defects, giving rise to ferromagnetic interlayer coupling, at low nonmagnetic layer thicknesses. Magnetic properties of the superlattice nanowires are influenced by in-plane anisotropy and magnetostatic coupling.

Multilevel Magnetoresistance in a Structure Consisting of two spin-valves

2001 ◽  
Vol 674 ◽  
Author(s):  
Kebin Li ◽  
Yihong Wu ◽  
Jinjun Qiu ◽  
Guchang Han ◽  
Zaibing Guo ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Data Storage ◽  
Giant Magnetoresistance ◽  
Structural Characteristics ◽  
High Vacuum ◽  
Spin Valve ◽  
Random Access ◽  
Interlayer Coupling ◽  
Blocking Temperature ◽  
Additional Processing

ABSTRACTThe magnetic and electrical properties as well as the structural characteristics have been studied on a series of samples with structure substrate (Sub)/SV(1)/Al2O35nm/SV(2). Here, SV(1) is either CoFe/IrMn based spin-valve (SV) such as Ta5/NiFe2/IrMn8/CoFe2/Cu2.6/CoFe2/Ta5 (thicknesses are in nanometers) bottom SV or Ta5/NiFe2/CoFe1.5/Cu2.6/CoFe2/FeMn10/Ta5 top SV and SV(2) is Ta5/NiFe2/CoFe1.5(or 2)/Cu2.6/CoFe2/IrMn8/Ta5 top SV. SV(1) and SV(2) in the structure are decoupled by a Al2O3 layer with 5nm in the magnetic properties, however, they are in parallel connection in the electrical properties. In a sample with structure Sub/Ta5/NiFe2/IrMn8/CoFe2/Cu2.6/CoFe2/Ta5/Al2O35/Ta5/NiFe2/CoFe2/Cu2.6/CoFe2/IrMn8/Ta5, five magnetoresistance states which are related to five magnetization states have been observed after the sample was annealed at T=220 °C with a field strength of 1T under high vacuum because of different interlayer coupling fields (Hint) in the top and bottom CoFe/IrMn based SVs (Hint is about 12.21 Oe in the top CoFe/IrMn SV and 29.3 Oe in the bottom CoFe/IrMn based SV). In a sample with structure Sub/Ta5/NiFe2/CoFe1.5/Cu2.6/CoFe2/FeMn10/Ta5/Al2O35/Ta5/NiFe2/CoFe1.5/Cu2.6/CoFe2 /IrMn8/Ta5, since the blocking temperature of the CoFe/FeMn based SV (Tb is about 150 °C) is lower than that of CoFe/IrMn based SV (Tb is about 230 °C), the spins can be easily engineered and therefore various magnetoresistance states can be obtained when the sample is magnetically annealed at different temperatures in a proper annealing sequence. By properly selecting materials and controlling the magnetically annealing conditions, multilevel giant magnetoresistance (MR) magnetic random access memory (MRAM) cell can be realized, which will significantly improve the MRAM data storage density without increasing any additional processing complexity.

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