PERPENDICULAR MAGNETIC ANISOTROPY AND MAGNETO-OPTICAL SPECTRA OF MBE GROWN MnPt3/Co MULTILAYERS

Abstract

MnPt/Co multilayer films were grown by the molecular-beam epitaxy (MBE) onto MgO( Ill) substrates at a temperature of 300 'c. Small angle XRD measurements demonstrated that the samples had multilayered structure with sharp MnPt/Co interfaces. The appearance of superlattice lines due to CU,Au structure confirmed a partial formation of the ordered phase in the MnPt, layers. The [MnPt,( 1.9 nm)/Co(O.4 nm)J lO multUayer showed a preferential magnetization perpendicular to the film plane and a 100% perpendicular remanence. The Ken spectrum of the multilayer had a negative peak of -0.24 deg around 1.4 eV and showed a enhancement in the high energy region. This result implies the existence of the ordered phase in the MnPt, layer and alloying layer of Co and Pt at the MnPt/Co interface.

Multilayer Diffraction Reveals That Colloidal Superlattices Approach the Structural Perfection of Single Crystals

“…σΛ<1.4 Å for Pb / amorphous Ge and σΛ≈0.5 Å for MgPt3/Co multilayers). 16,24,39 The σL values of 0.3-1.4 Å determined in this work are comparable to the atomic displacement parameters found in some metalorganic crystals (e.g. B=0.38 Å in silver behenate, a small-angle scattering standard) 40 , and roughly an order of magnitude smaller than the displacements reported for other colloidal nanocrystal superlattices (e.g.…”

Multilayer Diffraction Reveals That Colloidal Superlattices Approach the Structural Perfection of Single Crystals

“…Surprising at first, this result is comparable to the periodicity fluctuations measured in epitaxial multilayer thin films grown by physical means (e.g., σ Λ < 1.4 Å for Pb/amorphous Ge and σ Λ ≈ 0.5 Å for MgPt 3 /Co multilayers). 26,34,55 The σ L values of 0.33 to 1.43 Å determined in this work are comparable to the atomic displacement parameters found in some metalorganic crystals (e.g., B = 0.38 Å in silver behenate, a small-angle scattering standard) 56 and are roughly an order of magnitude smaller than the displacements reported for other colloidal nanocrystal superlattices (e.g., 0.5 to 0.9 nm in Fe 3 O 4 and 1.15 nm in FePt nanocrystal superlattices, both by GISAXS). 10,14 This high structural order poses a fundamental question: can colloidal superlattices be considered microscopic single crystals?…”