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Rare-earth iron-boron (RE-Fe–B) thin films with a c-axis texture were prepared on a Ta (110) buffer layer on thermally oxidized Si substrates by dc magnetron sputtering. The microstructure, magnetic structure, and magnetic properties of these films were studied as a function of the deposition temperature. The results show that c-axis texture can be obtained over a wide range of deposition temperatures and that the degree of c-axis orientation improves with deposition temperature. It was established that deposition of a RE-Fe–B thin film to obtain grains with a strong c-axis RE2Fe14B texture, coexisting with an amorphous phase, followed by annealing at higher temperature, is an effective route for obtaining excellent hard magnetic properties. Initial results show that a film, which was deposited at 470 °C and annealed at 590 °C, had a high perpendicular coercivity of 1.8 T, in combination with a large maximum energy product of 238 kJ/m3. [ABSTRACT FROM AUTHOR]

The exchange interactions for rapidly solidified (Nd/Pr)(Fe/Co)B hard magnetic alloys with remanence enhancement were studied by analyzing characteristic magnetic curves and Henkel plots. The exchange coupling can be improved by increasing soft phase content within hard matrix. With increasing temperature, the exchange interaction is enhanced due to the increased exchange length. An increased recoil susceptibility was found for the alloys with improved exchange coupling. Analysis of the microstructure parameters indicated that Co substituting Fe and introducing soft α-(Fe,Co) phase not only reduce the stray field effects but also enhance the exchange interaction. [ABSTRACT FROM AUTHOR]

To reduce the cost of the Nd–Fe–B magnets, the Ce element was suggested to be used as a replacement of Nd element. In this paper, nanocrystalline (Ce1–xNdx)16Fe78B6 ( x = 0 –0.7) alloys were prepared by melt spinning. The X-ray diffraction (XRD) results indicate that the alloys are composed of (NdCe)2Fe14B (2:14:1) phase and (CeNd)Fe2 (1:2) phase for 0 < 0.6, and the 1:2 phase was replaced by (NdCe) _{1+\varepsilon } Fe4B4 (1:4:4) phase when x = 0.6 and 0.7. The hyperfine parameters characteristics of the 2:14:1 phases were estimated from 300 K 57Fe Mössbauer spectra, as well as their contents and those of other intergranular phases. In addition to the 2:14:1, 1:2, and 1:4:4 phases, a small content of the rare earth-rich phase was also detected in all the alloys, which was not able to be observed by the XRD characterization. Based upon the hyperfine field, the average magnetic moment of Fe in 2:14:1 phase could be determined as 1.56, 1.62, 1.67, 1.73, 1.78, 1.83, 1.85, and 1.91~\mu \text {B} for x = 0 , 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.7, respectively. The minor change between the x = 0.5 ( 1.83~\mu _{\text {B}}) and x = 0.6$ ( 1.85~\mu _{\text {B}}) is discussed. Both the present local and macroscopic magnetic parameters significantly contribute to understand the fundamental role of Ce in those nanocrystalline Nd–Ce–Fe–B permanent magnets. [ABSTRACT FROM AUTHOR]

FePtSiN films consisting of FePt nanoparticles embedded in Si-rich matrix were fabricated on silicon substrates by direct current (dc) reactive magnetron sputtering followed by vacuum annealing. The effects of Si–N additions and annealing temperature on the structure and magnetic properties were investigated. The as-deposited films had face-centered cubic (fcc) structure, which transforms into the face-centered tetragonal (fct) structure after thermal annealing at 600 ^\circC. The grain size of FePt increased with the annealing temperature but decreased with increasing Si–N content. Increasing Si content led to the formation of Si–N-rich amorphous phase distributed between the FePt nanograins, which reduced the lattice distortion and increased the coercivity. The fct-FePt films annealed at 700 ^\circC exhibited very high coercivity, up to 13.6 kOe at room temperature and about 17.5 kOe at 100 K. These FePtSiN films have shown promise for high-density magnetic recording medium. [ABSTRACT FROM AUTHOR]

The electronic structures and magnetic properties of spinel Co1-x Zn (Cd)xFe2O4 (x = 0.0, 0.25, 0.5, 0.75, and 1.0) have been studied systematically by the first-principles calculation. The optimized structures show that with increasing Zn (Cd) content the crystal lattice parameter increases by 1.47% (5.13%) when the Co ions are completely replaced by Zn (Cd) ions. The results also indicate that the magnetic moment of Co/Fe ion increases and the total spin magnetic moment linearly increases with the Zn (Cd) doping from 3.00 μB for x = 0.0 up to 10.00 μB for x = 1.0 per formula unit. The electronic distribution in the Co spin-down subband is highly localized for the crystal field splitting between t2g and eg levels in the Zn (Cd) doped CoFe2O4 compounds and the energy band moves downwards while doped with Zn (Cd). Meanwhile, the bandgap decreases with the increase of Zn (Cd) except where x = 1 and the spinel structure is half-metal at some degree of doping. [ABSTRACT FROM AUTHOR]

Ultrafine BaFe12O19 powders are prepared by sol-gel combustion using glycine gels prepared from metal nitrates and glycine solutions which are ignited in a furnace after drying (220 °C, 1 min) prior to calcination in air at 700-1000 °C. [ABSTRACT FROM AUTHOR]