Showing papers in "Journal of Magnetism and Magnetic Materials in 2009"

TL;DR: In this article, a review of recent advances in the processing of microwave ferrites is presented, including self-bias magnetization, tunability of the magnetic anisotropy, low microwave loss, and volumetric and weight reduction.

TL;DR: In this article, an accurate method to determine the magnetic entropy change in materials with hysteretic first-order transitions is presented, which is needed to estimate their potential for applications.

TL;DR: In this article, commercial nanoparticles supplied by Chemicell, Micromod and Bayer-Schering were characterised with regard to their nanocrystalline diameter, hydrodynamic diameter, total iron content and relative ferrous iron content.

TL;DR: In this article, the formation of single-phase nickel ferrite nanoparticles in the range 8-28nm depending upon the annealing temperature of the samples during the synthesis was investigated.

TL;DR: It is unambiguously demonstrated, for the first time, that at a given frequency, heating rates of superparamagnetic particles are dependent on particle size, in agreement with earlier theoretical predictions.

TL;DR: In this article, a modified chemical coprecipitation route was used to synthesize CoFe 2 O 4 ferrite nanoparticles, and structural and magnetic properties were systematically investigated.

TL;DR: In this paper, the authors present mathematical modeling results that show how MPI sensitivity and spatial resolution both depend on the size of the nanoparticle core and its other physical properties, and how imaging performance can be effectively optimized through rational core design.

TL;DR: In this paper, the properties of Co x Zn 1− x Fe 2 O 4 (x = 0.0-1.0) nanoparticles synthesized by a polyethylene glycol (PEG)-assisted hydrothermal route were investigated.

TL;DR: In this paper, an analytical expression for calculating the attraction force between two cylindrical permanent magnets on the assumption of uniform magnetization was introduced, and a very good agreement between the calculated and measured forces between two identical cylinear magnets and within an array of NdFeB cylinrical magnets was obtained.

TL;DR: In this article, the authors reviewed recent progress in the field of microwave magnetic properties of composites and concluded that the validity of a mixing rule is determined by the permeability contrast in the composite, i.e., the difference between permeability of inclusions and the host matrix.

TL;DR: There are critical decisions and great challenges ahead for the key technologies of heads, media, head–disk interface, mechanics, and electronics.

TL;DR: In this article, the relative contributions of Neel and Brownian relaxations on magnetic heat dissipation were studied by investigating the physical, magnetic and heating characteristics of magnetite nanoparticle suspensions with average diameters of 12.5 and 15.7 nm.

TL;DR: In this article, the diamagnetically substituted polycrystalline samples of the diamagnetic substituted Bi 1−x A x A x FeO 3− x /2 (A=Ca, Sr, Pb, Ba; x =02, 03) have been investigated.

TL;DR: In this paper, water-soluble magnetite nanoparticles have been directly synthesized by thermal decomposition of iron (III) acetylacetonate, Fe(acac)3 in tri(ethyleneglycol).

TL;DR: In this paper, the authors investigated the role of the inhomogeneous distribution of fcc-Nd oxide whose volume fraction increased with respect to the dhcp Nd-rich phase.

TL;DR: This article is an attempt to provide a brief review of the research that has been carried out, interspersed with an analysis of possible new directions of magnetic recording.

TL;DR: In this paper, water-based suspensions of multicore nanoparticles were prepared by coating of the particles (synthesized by means of a modified alkaline precipitation method) with a carboxymethyldextran shell.

TL;DR: In this article, the authors studied magnetostructural transitions from paramagnetic austenite to ferromagnetic martesite phases at TMC in Ni 2 MnGa-based alloys.

TL;DR: In this article, a coating with flake carbonyl-iron particles as absorber and epoxy-silicone resins as matrix was prepared and the complex permittivity, complex permeability and microwave-absorbing properties were investigated in the frequency range of 2-18 GHz.

TL;DR: In this article, a solvent-free thermal decomposition method is reported for synthesizing Fe 3 O 4 nanoparticles, which can be tailored by adjusting either reaction temperature or reaction time.

TL;DR: In this paper, double-layer wave absorbing materials are composed of a matching layer and an absorption layer, and the total thickness of the double layer is the sum of the thicknesses of these two layers.

TL;DR: In this paper, the exchange spring behavior in the soft-hard ferrite composite was observed for the first time by tailoring the particle size of the individual phases and by suitable thermal treatment of the composite.

TL;DR: In this article, the magnetic properties of Ni0.58Zn0.42Fe2O4 were studied by superconducting quantum interference device and showed superparamagnetic behavior at room temperature (300 K) and negligible hysteresis at low temperature (5 K).

TL;DR: In this article, the effects of the shell coupling and the interface coupling on both the compensation temperature and the magnetization profiles are investigated, as well as their effects on the hysteresis loops.

TL;DR: In this article, the properties of Gd and Nd-substituted nickel ferrite were investigated and the existence of the ferroelectricity was confirmed from the Ferroelectric loops and magnetocapacitance of −2% and −3% were observed.

TL;DR: In this paper, the authors proposed a method to achieve Tb/in 2 and beyond recording densities by constructing sub-10nm discrete magnetic islands covering a full disk with tight spacing and size distributions and a narrow switching field distribution.

TL;DR: In this article, a copper doped ZnO nanoparticles were synthesized by the chemical technique based on the hydrothermal method and the crystallite structure, morphology and size were determined by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and scanning electron microscope (SEM) for different doping percentages of Cu 2+ (1-10%).

TL;DR: In this paper, X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), and vibrating scanning magnetometry (VSM) were used for the structural, morphological, and magnetic characterizations of the product.

TL;DR: In this article, the potential of exchange spring bilayers and graded media is reviewed, and an analytical model for the optimization of graded media gives an optimal value of the magnetic polarization of J s = 0.8 T.

TL;DR: In this paper, the magnetic behavior of the nanoparticles of ZnO with varying Fe doping concentration was investigated using a vibrating sample magnetometer (VSM), initially these nanoparticles showed strong ferromagnetic behavior, however at higher doping percentage of Fe, the ferromagnetism was suppressed and paramagnetic nature was observed.