scholarly journals Field dependences of the magnetization and exchange bias in ferro/antiferromagnetic systems. II. Continuum model of a ferromagnetic layer

2009 ◽  
Vol 35 (7) ◽  
pp. 526-530 ◽  
Author(s):  
A. G. Grechnev ◽  
A. S. Kovalev ◽  
M. L. Pankratova
Keyword(s):  
Exchange Bias ◽  
Continuum Model ◽  
Ferromagnetic Layer

Nonvolatile Electric Control of Exchange Bias by a Redox Transformation of the Ferromagnetic Layer

2019 ◽  
Vol 5 (6) ◽  
pp. 1900296 ◽  
Author(s):  
Jonas Zehner ◽  
Rico Huhnstock ◽  
Steffen Oswald ◽  
Ulrike Wolff ◽  
Ivan Soldatov ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Ferromagnetic Layer ◽  
Redox Transformation ◽  
Electric Control

Exchange Bias and Training Effect in Polycrystalline Antiferromagnetic/Ferromagnetic Bilayers

2002 ◽  
Vol 746 ◽  
Author(s):  
Markus Kirschner ◽  
Dieter Suess ◽  
Thomas Schrefl ◽  
Josef Fidler
Keyword(s):  
Layer Thickness ◽  
Exchange Bias ◽  
Ferromagnetic Layer ◽  
Bias Field ◽  
Training Effect ◽  
Hysteresis Cycle ◽  
Weak Exchange ◽  
Antiferromagnetic Layer ◽  
20 Nm ◽  
And Training

ABSTRACTExchange bias and training effect are simulated for IrMn/NiFe bilayers. As a function of the thickness of the antiferromagnet the bias field shows a maximum for a thickness of 22 nm. For decreasing antiferromagnetic thickness the domain wall energy approaches zero. For large thicknesses the high anisotropy energy hinders switching of the antiferromagnetic grains resulting in weak bias. Starting from the field cooled state as initial configuration a bias field of about 8 mT is obtained assuming a antiferromagnetic layer thickness of 20 nm, a ferromagnetic layer thickness of 10 nm, and a grain size of 10 nm. The next hysteresis cycle shows a reduction of the bias field by about 65%. Exchange bias and training effect in fully compensated antiferromagnet/ferromagnet bilayers are explained with a simple micromagnetic model. The model assumes no defects except for grain boundaries, and coupling is due to spin flop at a perfect interface. The simulations show that a weak exchange interaction between randomly oriented antiferromagnetic grains and spin flop coupling at a perfectly compensated interface are sufficient to support exchange bias.

scholarly journals Magnetoelectric Induced Switching of Perpendicular Exchange Bias Using 30-nm-Thick Cr2O3 Thin Film

2021 ◽  
Vol 7 (3) ◽  
pp. 36
Author(s):  
Yu Shiratsuchi ◽  
Yiran Tao ◽  
Kentaro Toyoki ◽  
Ryoichi Nakatani
Keyword(s):  
Thin Film ◽  
Quantitative Analysis ◽  
Electric Field ◽  
Layer Thickness ◽  
Exchange Bias ◽  
Ferromagnetic Layer ◽  
Switching Field ◽  
Domain State ◽  
Field Cooling

Magnetoelectric (ME) effect is a result of the interplay between magnetism and electric field and now, it is regarded as a principle that can be applied to the technique of controlling the antiferromagnetic (AFM) domain state. The ME-controlled AFM domain state can be read out by the magnetization of the adjacent ferromagnetic layer coupled with the ME AFM layer via exchange bias. In this technique, the reduction in the ME layer thickness is an ongoing challenge. In this paper, we demonstrate the ME-induced switching of exchange bias polarity using the 30-nm thick ME Cr2O3 thin film. Two typical switching processes, the ME field cooling (MEFC) and isothermal modes, are both explored. The required ME field for the switching in the MEFC mode suggests that the ME susceptibility (α33) is not deteriorated at 30 nm thickness regime. The isothermal change of the exchange bias shows the hysteresis with respect to the electric field, and there is an asymmetry of the switching field depending on the switching direction. The quantitative analysis of this asymmetry yields α33 at 273 K of 3.7 ± 0.5 ps/m, which is comparable to the reported value for the bulk Cr2O3.

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