Oscillatory magnetic coupling in amorphous CoSiB/Pt/CoSiB structure

This paper investigates the magnetic interaction between two CoSiB layers separated by a Pt layer. The CoSiB/Pt/CoSiB sandwich structures are grown using DC sputtering method. Anomalous Hall effect is measured at room temperature. The magnitudes of Hall voltage signals are oscillating as a function of the Pt thickness, resembling the oscillatory behavior observed for the Ruderman-Kittle-Kasuya-Yosida (RKKY) interaction. For 22 and 27 Å thickness, clear signals from the antiferromagnetic coupling have been seen in both AHE and magnetization data. In order to exploit the mechanism of indirect interlayer coupling, the AHE is also measured as a function of perpendicular field H_z in an external magnetic field of H_x or H_y parallel to the film plane. AHE results show a shift of hysteresis loop, similar to an exchange bias effect found in ferromagnetic/antiferromagnetic bilayer structure. This behavior is analyzed using the Stoner-Wohlfarth model.