A5003209847- Magnetic properties of thin films
- Metallic Glasses and Amorphous Alloys
- Theoretical and Computational Physics
- Magnetic Properties and Applications
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Magnetic Properties of Alloys
- Multiferroics and related materials
- Thermodynamic and Structural Properties of Metals and Alloys
- Copper Interconnects and Reliability
- Metallurgical and Alloy Processes
- Metal and Thin Film Mechanics
- Quantum and electron transport phenomena
- Rare-earth and actinide compounds
- Surface and Thin Film Phenomena
- Ferroelectric and Piezoelectric Materials
- Nanoporous metals and alloys
- Electrical and Thermal Properties of Materials
- Electromagnetic wave absorption materials
- Ion-surface interactions and analysis
- Material Science and Thermodynamics
- Magnetic Field Sensors Techniques
- Transition Metal Oxide Nanomaterials
- Electrodeposition and Electroless Coatings
Universidade Federal do Rio Grande do Sul
2006-2020
Universidade Federal do Rio Grande
2020
Universidade Estadual de Campinas (UNICAMP)
2005
Laboratoire de physique des Solides
1988-1990
Université Paris-Sud
1988-1990
McGill University
1977-1983
We have studied the magnetoresistance of (001)Fe/(001)Cr superlattices prepared by molecularbeam epitaxy. A huge is found in with thin Cr layers: For example, ${t}_{\mathrm{Cr}}=9$ \AA{}, at $T=4.2$ K, resistivity lowered almost a factor 2 magnetic field T. ascribe this giant to spin-dependent transmission conduction electrons between Fe layers through layers.
We describe the magnetic and transport properties of Fe(001)/Cr(001) superlattices grown on GaAs (001) by molecular-beam epitaxy characterized reflection high-energy electron diffraction (RHEED), Auger spectroscopy, x-ray diffraction, microscopy. For Cr layers thinner than about 30 Å behavior reveals strong antiferromagnetic couplings between Fe across layers. Polarized neutron experiments confirm existence an superstructure. discuss origin (AF) coupling. The Fe/Cr with AF interlayer...
It is known that the spin-chain compound Ca3Co2O6 exhibits very interesting plateaus in magnetization as a function of magnetic field at low temperatures. The origin them still controversial. In this paper we study thermal behavior with single-flip Monte Carlo simulation on triangular lattice and demonstrate decisive influence metastable states splitting ferrimagnetic 1/3 plateau below 10 K. We consider [Co2O6]n chains giant moments described by large Ising spins planar clusters open...
We studied the electronic conductivity and magnetic properties of quasi-one-dimensional ${\mathrm{Ca}}_{3}{\mathrm{Co}}_{2}{\mathrm{O}}_{6}$ single crystals. The results evidence a variable range hopping with temperature-induced crossover between one-dimensional (intrachain) three-dimensional (3D) transport opening Coulomb gap in d bands along ferromagnetic intrachain ordering. At low temperatures, an applied field induces large negative magnetoresistance (MR) apparent dissociation 3D Both...
The relation between giant magnetoresistance (GMR) and phase separated nanostructures in ${\mathrm{Cu}}_{90}{\mathrm{Co}}_{10}$ is studied using magnetotransport measurements together with transmission electron microscopy x-ray microanalysis. samples were melt-spun ribbons isochronally annealed up to 873 K, all show their grains a homogeneous spinodal decomposition characterized by long parallel Co-excess stripes. These stripes have 40-nm modulation periods develop along the crystalline...
Thermopower and resistivity have been measured on a series of ${\mathrm{Mg}}_{1\ensuremath{-}x}{\mathrm{Zn}}_{x}$ amorphous alloys ($0.2<x<0.35$) over the temperature range 4-300 K. The thermopower data cannot be explained basis simple Ziman model. Using two-component model, which can considered as an extreme simplification Faber-Ziman theory liquid-metal alloys, we were able to fit experimental entire compositions. success this model strongly implies that usual average properties...
whether they are published or not.The documents may come from teaching and research institutions in France abroad, public private centers.
In this work, the magnetization dynamics of soft magnetic materials is studied with aid transverse differential permeability μ(Iac,f,Hdc) spectra. Contributions to processes from domain wall motion and rotation can be extracted data which are in turn obtained impedance Z(Iac,f,Hdc) particular, an iteration method used extract data. The approach tested samples a very well known structure, namely (110)[001]FeSi3%. Permeability spectra were frequency range (100 Hz⩽f⩽100 kHz), probe current...
The thermopower and resistivity of a series ${\mathrm{Cu}}_{1\ensuremath{-}x}{\mathrm{Zr}}_{x}$ alloys have been measured between 2 300 K for $0.3<x<0.7$. composition dependence the results cannot be explained on basis simple Ziman liquid-metal model. Inclusion partial structure factors in Faber-Ziman sense considerably improves agreement with experiment. This improvement is almost entirely due to "cross" term containing Cu-Zr factor indicates crucial role played by this calculating thermopower.
Co(15 Å)/Ag(60 Å) multilayers produced by electron beam deposition on a 50 Å chromium buffer layer over Si(111) wafer have been studied magnetoresistance, saturation magnetization, coercivity, and anisotropy. Annealing at various temperatures produces striking effects the observed physical properties, such as an improvement value of magnetoresistance associated to ‘‘back-diffusion’’ process in Co/Ag interfaces. This leads one believe that interface roughness is indeed most important...
In this work, a study of the stress relief in Finemet ribbons, Fe73.5Cu1Nb3Si16.5B6, as function annealing temperature is presented. The melt-spun samples are amorphous and become partially crystallized after at appropriate temperatures. For temperatures TA⩾480 °C nanocrystalline, with microstructure composed by α-Fe1−xSix (x∼0.2) crystallites (10 nm average diameter) embedded an matrix. Nanocrystallization, associated effects, improves soft magnetic properties kind material. level was...
The present article investigates the relation between magnetoimpedance (MI) and evolution of magnetic domain structure along magnetization curves commercial FeSi3% sheets cut at different angles with respect to easy axis [001]. role magnetocrystalline anisotropy on MI is studied correlation basic features vs H (M) established. From data obtained appropriate frequency ranges, dependence effective transverse differential permeability obtained. field spectra impedance allow identification...