Training and recovery behaviors of exchange bias in FeNi/Cu/Co/FeMn spin valves at high field sweep rates

Abstract

Training and recovery of exchange bias in FeNi/Cu/Co/FeMn spin valves have been studied by magnetoresistance curves with field sweep rates from 1000 to 4800 Oe/s. It is found that training and recovery of exchange field are proportional to the logarithm of the training cycles and recovery time, respectively. These behaviours are explained within the model based on thermal activation. For the field sweep rates of 1000, 2000 and 4000 Oe/s, the relaxation time of antiferromagnet spins are 61.4, 27.6, and 11.5 in the unit of ms respectively, much shorter than the long relaxation time (∼ 10 2 s) in conventional magnetometry measurements.

Modeling the Training Effect in Exchange‐Biased Bilayers for Large Numbers of Magnetization Reversal Cycles

“…It must be mentioned that, in contrast to ref. [42], here a slightly modified function was used with to enable fitting the first parameter properly, similar to the modification of the original power law given in Equation (2).…”

“…[38] The thermomagnetic relaxation is often modeled logarithmically. [12,[39][40][41] For the TE, however, such a logarithmic relaxation has rarely been applied, e.g., for 50 cycles of magnetization reversal in FeNi/Cu/Co/FeMn [42] H…”

“…[ 38 ] The thermomagnetic relaxation is often modeled logarithmically. [ 12,39–41 ] For the TE, however, such a logarithmic relaxation has rarely been applied, e.g., for 50 cycles of magnetization reversal in FeNi/Cu/Co/FeMn [ 42 ] with fitting constants A and B .…”

Effect of Magnetic Field and Temperature on the Exchange Bias in Phase-Separated Nd1-xSrxCoO3(x=0.10, 0.15)

“…Ever since, people have found exchange bias at FM-AFM /Ferri-FM/Ferri-AFM interfaces [1][2][3][4][5][6]. Exchange bias exists in mono-crystal and poly-crystal samples and thin film samples [7][8][9][10][11][12][13][14][15], suggesting that exchange bias is an internal trait of these systems, but not related to synthesis methods. In the recent years, exchange bias has also been found in the spin glass.…”