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We present a near-field diffraction model for spin waves in perpendicularly magnetized films applicable in any geometries of excitation fields. This model relies on Kalinikos–Slavin formalism to express the dynamic susceptibility tensor in k-space and calculate the diffraction patterns via inverse 2D-Fourier transform of the response functions. We show an excellent quantitative agreement between our model and MuMax3 micro-magnetic simulations on two different geometries of antennas. Our method benchmarks spin wave diffraction in perpendicularly magnetized films and is readily applicable for future designs of magnon beamforming and interferometric devices. [ABSTRACT FROM AUTHOR]

Reflection high-energy electron diffraction (RHEED) analysis of epitaxial Co/Mn superlattices grown on hcp(0001) Ru buffer layers reveals that Mn conformation changes from its sixfold in-plane symmetric close-packed structure to a structure that is similar to the Cu2Mg Laves phases and the alpha-Mn phase. The modification takes place following partial relaxation of the in-plane parameter of the Mn lattice and at a critical thickness of 5 to 6 monolayers. The modified Mn structure induces the coexistence of gamma-Mn and Cu2Mg structures with the crystal domains in the superlattices.

The magnetic properties of amorphous Co(sub 73 plusmn x plusmn y)Zr5Gd(sub 14 plusmn x)Dy(sub 8 plusmn y) thin films with x ~ 2 and y ~ 1 are discussed. The rapid shift in temperature composition results in strong variation in the value of 4 pi Ms with a slight change in the size of perpendicular and in-plane uniaxial anisotropy.

A study was conducted to analyze a new technique for pinning the magnetization of the magnetically hard subsystem in micron-size magnetic tunnel junctions. The tunnel barriers were formed by sputter etching deposited aluminum layers in a rf Ar/O2 plasma. Wafers were then patterned into arrays of square junctions. Experimental results indicated that the tunnel magnetoresistance was independent of the junction size.

A combined atomic force microscopy/scanning tunneling microscope has been used to map the tunnel current flowing through metal/oxide stacks, in order to obtain a nanoscopic insight into the origins of fluctuations. Total conductance of imperfect metal/oxide junctions is found to be dominated by very few sites, enabling the sample-to-sample conductance fluctuations to be relating to slight variations of tunnel barrier parameters.

Ferromagnetic resonance simulations indicate major fcc structures in lattices with minimal Mn thickness and hcp structures in the lattices with Mn thickness greater than 12 angstrom units. The predominant hcp structures have minor fcc 10 phase inclusions with large magnetocrystalline anisotropic values.

The inelastic, spin-dependent tunneling in magnetic junctions with AlOx barrier and Co50Fe50 ferromagnetic (FM) electrodes is discussed. There is less decline of JMR with temperature for the annealed junctions and the maximum decrease of JMR is measured for the overoxidised as-deposited junctions.

Magnetic tunnel junctions are fabricated, that use Co/Ru/Co and Co/Ru/CoFe artificial ferrimagnet (AFi) systems as hard magnetic electrodes. Together with the enhanced thermal stability, up to 350 degree Celsius of the junctions involving the Co/Ru/CoFe system potential use as magnetic sensors is discussed.

The impact of the micromagnetic configuration within the ferromagnetic layers on transport properties of hard/soft magnetic tunnel junctions is presented. An artificial ferrimagnetic (AFi) trilayer structure is used as a magnetically hard subsystem.

Sr2FeMoO6(70 nm)/SrTiO3(3 nm)/CoFe2O4(30 nm) magnetic tunnel junctions are grown by pulsed laser deposition and patterned using optical lithography. The square tunnel elements with lateral size of 50 μm exhibit nonlinear zero-field current-voltage (I-V) variation. More interesting, when the temperature is decreased, the I-V curves become highly asymmetric and present a diodelike behavior. In order to explain this behavior, ab initio calculations are performed to obtain the electronic structure for each oxide layer. It is shown that our structure behaves like a usual metal/insulator/semiconductor diode due to the small gap into the majority-spin band of the CoFe2O4 layer. Finally, we point out that the I-V characteristic can be magnetically controlled. [ABSTRACT FROM AUTHOR]

The present work reports on the inelastic, spin-dependent tunneling in magnetic junctions with AlOx barrier and Co50Fe50 ferromagnetic (FM) electrodes. The identification of the transport inelastic channels is possible through their distinctive temperature dependencies. For the observed temperature behavior of the magnetotransport properties of the junctions, two spin-dependent, inelastic mechanisms are proposed: assisted tunneling due to interfacial (a) magnons and (b) metallic phonons. Their relative contributions are closely linked to the microstructural properties of the FM metal/oxide interfaces, related to the plasma oxidation of the tunnel barrier and to thermal annealing. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Amorphous CO[sub 73] ± χ ±yZr[sub 5]Gd[sub 14] ± χ Dy[sub 8 ± y] thin films with x ≈ 2 and y ≈ 1 were prepared by rf sputtering in the presence of a dc field applied along the film plane. The films exhibit a perpendicular H[sub p] and an in-plane H[sub u], anisotropy related to the clusters formed around Gd and Dy, respectively. Here H[sub p]>4 π M[sub s], while the respective values of 4 π M[sub s] and H[sub u], so the magnetic properties changed with composition. The behavior of the stripe domains is classical for 4 π M[sub s] > H[sub u], but affected by H[sub u] for 4πM[sub s] ∼ H[sub u]. When H[sub u] > 4 π M[sub s] perpendicular domains sensitive to high perpendicular fields and in-plane domains to low ones are observed. [ABSTRACT FROM AUTHOR]

Presents a study which determined the ferromagnetic resonance (FMR) of fcc→hcp structural change in epitaxial cobalt/manganese superlattices. Background on FMR; Results of the study.

Reports the development of a combined atomic force microscope/scanning tunneling setup to map the tunnel current that flows through metal/oxide stacks. Characteristics of magnetic tunnel junctions; Analysis of electrical images; Workability of this development.

Investigates the measurement of the phosphorus nuclear spin-lattice relaxation rate in the quasi-two-dimensional XY antiferromagnet barium-nitrogen. Field dependence observed for H parallel; Occurrence of three dimensional magnetic ordering; Relaxation rate for the phosphorus nuclear spins.