The Influence of Quantum Size Effects on Magnetic Properties of Thin-Film Systems

Abstract

Results on the investigation of magnetic and magneto-optical properties of Fe/NML/Fe (NML: Mo, Ta) thin-film systems are presented. The examined samples were prepared by DC magnetron sputtering technique. The hysteresis loops and spectral dependencies of the transverse Kerr effect (TKE) were measured employing the magneto-optical magnetometer and the magneto-optical spectrometer, respectively. The saturation field of the examined trilayers was revealed to oscillate as a function of the NML layer thickness, and the period of these oscillations to depend on the Fe layer thickness. The TKE spectra of the studied systems were found to be identical but the TKE values depend on the thickness of both Fe and Mo, Ta layers.

Influence of Bi on the magnetic and magneto-optical properties of Co/Bi/Co and Bi/Co thin-film systems

“…4. According to previously reported experimental data [6][7][8] and calculations, 25) the double-stage and almost rectangular hysteresis loops are observed for antiparallel and parallel orientations of magnetization components in cobalt layers. Thus, the dependences of H C (t Bi ) and H S (t Bi ) for the Co=Bi=Co samples suggest the existence of ferromagnetic (F) and antiferromagnetic (AF) exchange interactions between Co ferromagnetic layers through the Bi interlayer.…”

“…The range of coupling extends up to the spacer layer of approximately 500 Å, which is larger than that of trilayer samples with metal spacers. For example, in the cases of the Fe=Mo, Ta=Mo, 7) and Co=Si=Co 8) samples the ranges of coupling are about 40 and 34 Å, respectively. The average value of Λ at t Bi > 40 Å is on the order of 150 Å.…”

The Influence of Si on Magnetic and Magneto-Optical Properties of Co/Si/Co Thin-Film Systems

“…So, the above mentioned features of the Co/Si/Co samples determine the observed behaviour of H S (t Si ) at t Si < 1.6 nm. According to experimental data and calculations [11,12], the two-step hysteresis loops testify the antiparallel Achievements in Magnetism of magnetization in the cobalt layers and, hence, the evidence of the antiferromagnetic exchange interaction between ferromagnetic layers through the silicon spacer. Therefore, the dependence H S (t Si ) at t Si > 1.6 nm can be explained by variation of the constant of antiferromagnetic exchange, J AF , between the cobalt layers with t Si increase [11].…”

“…According to experimental data and calculations [11,12], the two-step hysteresis loops testify the antiparallel Achievements in Magnetism of magnetization in the cobalt layers and, hence, the evidence of the antiferromagnetic exchange interaction between ferromagnetic layers through the silicon spacer. Therefore, the dependence H S (t Si ) at t Si > 1.6 nm can be explained by variation of the constant of antiferromagnetic exchange, J AF , between the cobalt layers with t Si increase [11]. The possible mechanism of the exchange coupling between the Co layers via the Si interlayer is the tunnelling of polarized electrons via localized defects which are always present in the semiconductor layer [13,14].…”