0000000000006806
AUTHOR
Gan Moog Chow
Spin and Orbital Magnetic Moments of FePt Thin Films
The magnetic moments of disordered and ordered L10 Fe50Pt50 films were investigated using magnetic circular dichroism (MCD) and spin polarized full relativistic Korringa–Kohn–Rostoker (SPRKKR) calculations. The measurements showed that the spin magnetic moments of Fe in both ordered and disordered films were similar with a lower value than that obtained by SPRKKR calculations. Both films however showed larger orbital moments of Fe compared to the calculations. It is suggested that the spin magnetic moment of Fe in FePt thin films was insensitive to L10 ordering.
Electrical switching of perpendicular magnetization in a single ferromagnetic layer
We report on the efficient spin-orbit torque (SOT) switching in a single ferromagnetic layer induced by a new type of inversion asymmetry, the composition gradient. The SOT of 6- to 60-nm epitaxial FePt thin films with a $L{1}_{0}$ phase is investigated. The magnetization of the FePt single layer can be reversibly switched by applying electrical current with a moderate current density. Different from previously reported SOTs which either decreases with or does not change with the film thickness, the SOT in FePt increases with the film thickness. We found the SOT in FePt can be attributed to the composition gradient along the film normal direction. A linear correlation between the SOT and th…
Investigation of Elemental Magnetic Moments of CoCrPt Films Using X-Ray Magnetic Circular Dichroism
The elemental magnetic moments of Co and Cr in CoCrPt films were investigated using xray magnetic circular dichroism (XMCD). The spin and orbital moments of Co was calculated using the sum rules; it was found that the magnetic moment of Co in CoCrPt films was dominated by spin moment contribution. The total magnetic moment of Co was found to be lower than that of bulk Co. Further, the Cr moment was aligned anti-ferromagnetically with respect to Co, resulting in a decrease of saturation magnetization (Ms) in CoCrPt films.
Photoabsorption and MXCD in photoemission microscopy for characterisation of advanced materials
Abstract We applied chemical and magnetic sensitive photoemission electron microscopy (PEEM) to investigate surfaces of advanced materials. PEEM at low photon energies provides a high spatial resolution, but suffers from the lack of information about the chemical composition of the imaged surface. Such information can be obtained by PEEM via tuning the photon energy to X-ray absorption edges. To apply spectromicroscopy we acquired and subtracted microscopic images using photon energies just below and at the edges. The resulting difference gives a micro-image of the lateral distribution of a specific element. Microspectroscopy is performed by recording the intensity of secondary electrons in…
Field dependence of spin and orbital moments of Fe in L10 FePt magnetic thin films
Abstract The field dependence of spin and orbital magnetic moments of Fe in L10 FePt magnetic thin films was investigated using X-ray magnetic circular dichroism (XMCD). The spin and orbital moments were calculated using the sum rules; it was found that the spin and orbital moment of Fe in L10 FePt films are ∼2.5 and 0.2 μB, respectively. The relative XMCD asymmetry at Fe L3 peak on the dependence of applied field suggested that the majority magnetic moment of L10 FePt films resulted from Fe.