TY  - JOUR
AU  - Paul, Amitesh
AU  - Schmidt, C.
AU  - Paul, N.
AU  - Ehresmann, A.
AU  - Mattauch, Stefan
AU  - Böni, Peter
TI  - Symmetric magnetization reversal in polycrystalline exchange coupled systems via simultaneous processes of coherent rotation and domain nucleation
JO  - Physical review / B
VL  - 86
IS  - 9
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2015-03368
SP  - 094420
PY  - 2012
AB  - Training in exchange bias systems plays an essential role in understanding the very origin of the biasing effect. The nonequilibrium arrangement of antiferromagnetic (AF) spins at the antiferromagnetic-ferromagnetic interface, related to the AF uniaxial anisotropy, plays a crucial role during the initial training. Our system of choice, IrMn/CoFe, possesses softer uniaxial anisotropy compared to other AF systems (e.g., CoO), thereby reducing the energy penalty due to nonequilibrium spins. Different methods have been applied to initialize or modify the unidirectional anisotropy. We apply an in-plane field (a) during field growth, (b) during field cooling below its blocking temperature, and (c) in an in-plane magnetic field during ion irradiation, along and opposite the field applied during field growth. Magnetization reversal mechanisms were investigated during the first two field cycles to identify the role of each method on the training. A detailed analysis of polarized neutron scattering using the distorted wave Born approximation reveals a simultaneous process of domain nucleation and coherent rotation for magnetization reversal.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000308736400003
DO  - DOI:10.1103/PhysRevB.86.094420
UR  - https://juser.fz-juelich.de/record/201058
ER  -