antiferromagnetic materials;
chromium;
critical currents;
current density;
ferromagnetic materials;
ferromagnetic resonance;
iron;
magnetic structure;
magnetic thin films;
magnetisation;
metallic thin films;
PHASE-LOCKING;
FE LAYERS;
DRIVEN;
EXCITATION;
DEVICES;
CR;
D O I:
10.1063/1.3143625
中图分类号:
O59 [应用物理学];
学科分类号:
摘要:
In order to understand the effect of spin-transfer-torque (STT) on artificial magnetic structures, STT-induced and magnetic field-induced ferromagnetic resonances (FMRs) were investigated for Fe/Cr/Fe layers with an antiferromagnetic coupling field. The magnetic field-induced FMR showed high resonant frequency at zero magnetic field owing to the antiferromagnetic coupling field. FMR modes characteristic of antiferromagnetic coupling were induced by STT. From the STT-FMR spectra, the critical current density for magnetization instability was estimated to be similar to 7x10(7) A/cm(2), suggesting the possibility that STT gives rise to the dynamic phase of magnetization in such artificial magnetic structures.