Browsing Exact and Earth Sciences by Title
Now showing items 2927-2946 of 5964
-
Magnetic materials enriched with strontium : a study of the use as catalysts in the transesterification reaction of babassu oil
(2019) [Journal article]This work described a new magnetic material enriched with strontium as catalyst to produce babassu biodiesel. The use of magnetic materials has attracted attention due to easy and fast separation from reaction medium. ... -
Magnetic ordering in YGd alloys
(1985) [Journal article]We present magnetization and resistivity measurements on single crystals of yttrium doped with small concentrations of gadolinium (c = 1, 2, and 3 at. %). The low-field susceptibility exhibits a spin-glass-like sharp cusp ... -
Magnetic properties of Nd/Fe double layers grown on Si(111) by electron beam evaporation
(1998) [Journal article]In-plane ferromagnetic resonance (FMR) has been used to study the room-temperature magnetic and crystalline properties of Nd/Fe bilayers. Several samples were grown by electron beam evaporation onto Si(111) substrates, for ... -
Magnetic susceptibility and specific heat of the anderson lattice : perturbative expansion around the atomic limit
(1992) [Journal article]The Green's functions relevant to the periodic Anderson Hamiltonian are calculated via perturbation theory around the atomic limit. The approximation reproduces exact results in three different limits: zero bandwidth, zero ... -
Magnetic susceptibility of fe/cu multilayers : ferromagnetic, antiferromagnetic, and spin-glass phases
(1998) [Journal article]In this work we present low-field magnetic measurements on multilayers of Fe 1.5 nm and Cu 1.5 nm layers, repeated 10 times, grown on Si~111! and Fe 5 nm/CaF2 40 nm/Si(111), substrates. Magnetic characteristics of a ... -
Magnetic white dwarf stars in the Sloan Digital Sky Survey
(2013) [Journal article]To obtain better statistics on the occurrence of magnetism among white dwarfs, we searched the spectra of the hydrogen atmosphere white dwarf stars (DAs) in the Data Release 7 of the Sloan Digital Sky Survey (SDSS) for ... -
Magnetism and quantum phase transitions in spin-1/2 attractive fermions with polarization
(2009) [Journal article]An extensive investigation is given for magnetic properties and phase transitions in one-dimensional (1D) Bethe ansatz integrable spin-1/2 attractive fermions with polarization by means of the dressed energy formalism. An ... -
Magnetism in dilute magnetic oxide thin films based on SnO/sub 2/
(2006) [Journal article]Thin films of SnO2 prepared by pulsed-laser deposition on R-cut sapphire substrates exhibit ferromagnetic properties at room temperature when they are doped with Cr, Mn, Fe, Co, or Ni, but not with other 3d cations. ... -
Magnetism, magnetoresistance, and Shubnikov-de Haas oscillations in Na-implanted highly oriented pyrolitic graphite
(2012) [Journal article]We report on magnetization, magnetoresistance, and Shubnikov-de Haas oscillations experiments in Na-implanted samples of highly oriented pyrolitic graphite (HOPG). Different ion fluences were applied so that samples with ... -
Magnetization dynamics as derived from magneto impedance measurements
(2000) [Journal article]In this work, the magnetization dynamics of soft magnetic materials is studied with the aid of transverse differential permeability μ(Iac , f ,Hdc) spectra. Contributions to the magnetization processes from domain wall ... -
Magnetization dynamics in nanostructures with weak/strong anisotropy
(2014) [Journal article]We investigate the high-frequency response of magnetization dynamics through magnetoimpedance (MI) effect in Permalloy-based multilayered thin films produced with two different non-magnetic metallic spacers: Cu and Ag. Due ... -
Magnetization process and magnetoimpedance in (110)[001]FeSi/Sub 3%
(1998) [Journal article]The present article investigates the relation between magnetoimpedance (MI) and the evolution of the magnetic domain structure along the magnetization curves of commercial FeSi3% sheets cut at different angles with respect ... -
Magnetoconductivity of a disordered electron system with n orbitals persite
(1994) [Journal article]In the absence of a magnetic field, two formally equivalent expressions for the conductivity contribute different sets of Feynman diagrams, due to cancellations. We use this result to calculate the magnetoconductivity of ... -
Magnetoelectric effect and phase transitions in CuO in external magnetic fields
(2016) [Journal article]Apart from being so far the only known binary multiferroic compound, CuO has a much higher transition temperature into the multiferroic state, 230 K, than any other known material in which the electric polarization is ... -
Magnetometria in-situ para caracterização de materiais eletrodepositados
(2019) [Journal article]We have recently made studies of electrodeposits of Co onto graphene attached to different substrates, successfully performed via in-situ magnetization measurements. The magnetic analysis of deposits as a function of time ... -
Magnetoresistance in rf-sputtered(nife/cu/co/cu) spin-valve multilayers
(1993) [Journal article]A study of the vtiation of the magnetoresistancein (Ni80Fe20/Cu/Co/Cu) multilayers with the thicknesses tNiFe, tcO, and &;cu of each type of component layer has been performed. The magnetoresistance (MR), which at 4 .2 K ... -
Magnetoresistance of doped silicon
(2015) [Journal article]We have performed longitudinal magnetoresistance measurements on heavily n-doped silicon for donor concentrations exceeding the critical value for the metal-nonmetal transition. The results are compared to those from a ... -
Magnetoresistance of pd-fe and pd-ni-fe alloys
(1983) [Journal article]The electrical resistivity ofPd-Fe alloys has been measured in magnetic fields parallel and perpendicular to the current, for a wide range of alloy compositions. The influence of atomic ordering on the magnetoresistance ... -
Magnetosonic waves in a quantum plasma with arbitrary electron degeneracy
(2018) [Journal article]Using a two-species quantum hydrodynamic model, we derive the quantum counterpart of magnetosonic waves, in a plasma with arbitrary degree of degeneracy and taking into account quantum diffraction effects due to the ... -
Magnetostriction in ar/sup +/ implanted and annealed co/pd multilayers
(1995) [Journal article]Magnetostriction curves with (111) textured polycrystalline Co/Pd multilayers, as deposited or submitted to ArS ion implantation or thermal annealing, are presented and discussed. Both treatments, while promoting intermixing ...