Engineering the Exchange Spin Waves in Graded Thin Ferromagnetic Films.

The results of experimental and theoretical studies of standing spin waves in a series of epitaxial films of the ferromagnetic Pd1−xFex alloy (0.02 < x < 0.11) with different distributions of the magnetic properties across the thickness are presented.

Ultrafast signatures of magnetic inhomogeneity in Pd Fe ( ≤ 0.08) epitaxial thin films.

A series of Pd Fe alloy epitaxial films ( = 0, 0.038, 0.062, and 0.

Density Functional Theory Approach to the Vibrational Properties and Magnetic Specific Heat of the Covalent Chain Antiferromagnet KFeS.

Ternary potassium-iron sulfide, KFeS, belongs to the family of highly anisotropic quasi-one-dimensional antiferromagnets with unusual "anti-Curie-Weiss" susceptibility, quasi-linearly growing with a rising temperature up to 700 K, an almost vanishing magnetic contribution to the specific heat, drastically reduced magnetic moment, etc. While some of the measurements can be satisfactorily described, the deficiency of the entropy changes upon the magnetic transition and the spin state of the iron ion remains a challenge for the further understanding of magnetism. In this work, high-quality single-crystalline samples of KFeS were grown by the Bridgman method, and their stoichiometry, crystal structure, and absence of alien magnetic phases were checked, utilizing wave-length dispersive X-ray electron-probe microanalysis, powder X-ray diffraction, and Fe Mössbauer spectroscopy, respectively.

Controllable two- and three-state magnetization switching in single-layer epitaxial Pd Fe films and an epitaxial PdFe/Ag/PdFe heterostructure.

We have investigated the low-temperature magnetoresistive properties of a thin epitaxial PdFe film at different directions of the current and the applied magnetic field. The obtained experimental results are well described within an assumption of a single-domain magnetic state of the film. In a wide range of the appled field directions, the magnetization reversal proceeds in two steps via the intermediate easy axis.

Synthesis, Characterization, and Magnetoresistive Properties of the Epitaxial PdFe/VN/PdFe Superconducting Spin-Valve Heterostructure.

A thin-film superconductor(S)/ferromagnet(F) F1/S/F2-type PdFe(20 nm)/VN(30 nm)/PdFe(12 nm) heteroepitaxial structure was synthesized on (001)-oriented single-crystal MgO substrate utilizing a combination of the reactive magnetron sputtering and the molecular-beam epitaxy techniques in ultrahigh vacuum conditions. The reference VN film, PdFe/VN, and VN/PdFe bilayers were grown in one run with the target sample. In-situ low-energy electron diffraction and ex-situ X-ray diffraction investigations approved that all the PdFe and VN layers in the series grew epitaxial in a cube-on-cube mode.

Mathematical description data: Spin-resolved electron transport in nanoscale heterojunctions: Theory and applications.

This study demonstrates a mathematical description of a point-like nanocontact model, which is developed to simulate electron transport through a nanoconstriction between magnetic or non-magnetic contact sides. The theory represents a solution to the quasi-(semi)-classical transport equations for charge current, which takes into account second-order derivatives of the related quasi-classical Green functions along the transport direction. The theoretical approach also enables the creation of an model for a heterojunction with embedded objects, where the initial condition, a conduction band minimum profile of the system, is well-defined.

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates.

Single-layer vanadium nitride (VN) and bilayer PdFe/VN and VN/PdFe thin-film heterostructures for possible spintronics applications were synthesized on (001)-oriented single-crystalline magnesium oxide (MgO) substrates utilizing a four-chamber ultrahigh vacuum deposition and analysis system. The VN layers were reactively magnetron sputtered from a metallic vanadium target in Ar/N plasma, while the Pd Fe layers were deposited by co-evaporation of metallic Pd and Fe pellets from calibrated effusion cells in a molecular beam epitaxy chamber. The VN stoichiometry and Pd Fe composition were controlled by X-ray photoelectron spectroscopy.

Thickness dependence of the triplet spin-valve effect in superconductor-ferromagnet-ferromagnet heterostructures.

Background: In nanoscale layered S/F1/N/F2/AF heterostructures, the generation of a long-range, odd-in-frequency spin-projection one triplet component of superconductivity, arising at non-collinear alignment of the magnetizations of F1 and F2, exhausts the singlet state. This yields the possibility of a global minimum of the superconducting transition temperature T c, i.e.