Influence of replacing Sr ions by rare-earth ions (RE) ions on the structural and magnetic properties of high coercivity (Hc) SrFe10Al2O19 hexaferrite have been investigated using X-ray diffraction, transmission electron microscopy, differential scanning calorimeter, and SQUID. A 73% increase in intrinsic coercivity is observed for Al doped SrFe10Al2O19 as compared to that of pure SrFe12O19. Th...

The high-temperature coercivity of mechanically alloyed and subsequently annealed RCo5 (R= Sm and Y) is studied. The annealed materials have the hexagonal CaCu5 structure with 2 : 17 (or 1 : 7) regions as a minor phase. High-temperature magnetic measurements show that the coercivities of materials decrease with increasing temperature from room-temperature to 873 K, but that the temperature coef...

The effect of Fe, Cu, Zr, and Ti substitution on magnetic properties of SmCo 1 : 7 magnets at temperatures up to 500 C were studied. As-milled amorphous Sm(Co,Fe,Cu,Ti–Zr)7 magnets crystallized in the TbCu7-type structure after annealing at 750 C for 2 h. A room-temperature intrinsic coercivity of around 2.5 T is obtained for compositions SmCo6 4Zr0 2Ti0 4 and SmCo6 4Fe0 1Zr0 1Ti0 4. The high c...

In magnetic random access memory (MRAM), power consumption depends on the coercivity of the magnetic elements in the memory cells. In this paper a new method is described that uses a “domain wall trap” element shape to reduce both the coercivity and the dependence of coercivity on element size in submicron magnetic elements. Micromagnetic simulations of a shaped Permalloy element show coercivit...

We report experimental evidence that submicron-scale local coercivity variation determines magnetization reversal dynamics in ferromagnetic thin films. Local coercivity distribution is generated from a twodimensional array of hysteresis loops each of 0.3230.32 mm spots simultaneously measured using a magneto-optical microscope magnetometer. We directly demonstrate that domain reversal pattern i...

A reduction process of the substituted Ba-ferrite has been found to be devided into three steps. At the first and second steps, the magneto-plumbite structure maintains and the coercivity increases. When the reduced-substituted Ba-ferrite particles are reoxidized, the coercivity is reversible in the first step but irreversible in the second step. During the third step, the magneto-plumbite stru...

Magnetic nanoparticles of cobalt ferrite (CoFe204) have been synthesized using water-in-oil microemulsions consisting of water, cetyl trimethyl ammonium bromide (surfactant), n-butanol (cosurfactant), and n-octane (oil). Precursor hydroxides were precipitated in the aqueous cores of water-in-oil microemulsions and these were then separated and calcined to give the magnetic oxide. X-ray diffract...

Ensembles of fcc nickel nanowires have been synthesized with defined mean sizes in the interior of single-wall carbon nanotubes. The method allows the intrinsic nature of single-domain magnets to emerge with large coercivity as their size becomes as small as the exchange length of nickel. By means of X-ray magnetic circular dichroism we probe electronic interactions at nickel-carbon interfaces ...