We measure the band structure of nickel along various high-symmetry lines of the bulk Brillouin zone with angle-resolved photoelectron spectroscopy. The Gutzwiller theory for a nine-band Hubbard model whose tight-binding parameters are obtained from non-magnetic density-functional theory resolves most of the long-standing discrepancies between experiment and theory on nickel. Thereby we support the view of itinerant ferromagnetism as induced by atomic correlations.

We report the effect of epitaxial growth and lattice mismatch on the enhancement of saturation magnetization (Ms) of ferromagnetic γ′-Fe4N thin films deposited on different single crystal substrates having lattice mismatches from 0% to 11%. It was found that Ms in the γ′-Fe4N film increased with increasing degree of epitaxy and minimizing lattice mismatch between the film and the substrate. Maximum saturation magnetization of 1980±20emu∕cm3 (about 24% higher than previous result) was obtained with LaAlO3(100) substrate having zero lattice mismatch after postannealing of 30min, which is believed to originate from magnetovolume effect in well-ordered epitaxially grown films.

Articles you may be interested inMagneto-electric effects in functionally stepped magnetic nanobilayers on ferroelectric substrates: Observation and theory on the influence of interlayer exchange coupling

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Recent progress in x-ray optics has pushed the lateral resolution of soft x-ray magnetic microscopy to below 15 nm. We have measured local magnetic hysteresis on a nanometer scale at the full-field x-ray microscope XM-1 at the Advanced Light Source in Berkeley, approaching fundamental length scales such as exchange lengths, Barkhausen lengths, and grain diameters. We have studied the evolution of magnetic domain patterns in a nanogranular CoCrPt film with a pronounced perpendicular magnetic anisotropy and revealed nanoscopic details associated with the granular film structure. From a quantitative analysis of the field-dependent magnetic domain patterns, we are able to generate local magnetic hysteresis map on a nanometer scale. Our findings indicate a significant variation of local coercive fields corresponding to the nanoscopic behavior of magnetic domains.