Synthesis and magnetic properties of gold coated iron oxide nanoparticles J. Appl. Phys. 105, 07B504 (2009); 10.1063/1.3059607 Synthesis of self-assembled monodisperse 3 nm FePd nanoparticles: Phase transition, magnetic study, and surface effectThe monodisperse Fe 3 O 4 nanocubes with controllable sizes from 6.5 to 30.0 nm have been synthesized in one pot. The shape-induced texture of the self-assembled nanocube superlattices has been deposited onto substrates by a convective assembly technique. The cubelike shapes affect the crystalline orientation of individual particles within the self-assembled superlattices compared with the nanoparticles with an isotropic spherical shape. The nanocubes with a size less than 25 nm show a typical superparamagnetic behavior at room temperature. Comparison of the hysteresis loop at 5 K of cubes with different sizes reveals a size-dependent behavior of saturation magnetization and coercivity.

No abstract

Single-phase α''-Fe16N2 nanoparticles have been synthesized with high reproducibility in gram amounts for the first time. The nanoparticles were obtained through the various kinds of successive procedure starting from the reduction of Fe-oxides, followed by nitriding in an atmosphere with very low moisture and oxygen contents of less than 1 ppm through the entire process. The single-phase α''-Fe16N2 nanoparticles exhibited saturation magnetization (Ms) of 234 emu/g at 5 K and a magnetocrystalline anisotropy constant (Ku) of 9.6×106 erg/cm3. These magnetic properties of this α''-Fe16N2 nanoparticles suggest that a new path for a possible candidate of the rare-earth-free permanent magnet material with a high Ms.

No abstract

Monodisperse Fe nanoparticles with a high saturation magnetization were synthesized by thermal decomposition of a newly developed Fe(CO) x -oleylamine reacted precursor. The coordinate bond of the Fe(CO) x -oleylamine reacted precursor is different from conventional Fe(CO) 5 , and the CO ligands are partially replaced by oleylamine. The coordinate bond of the Fe(CO) x -oleylamine reacted precursor had a large influence on the size of the Fe nanoparticles, and as a result, the nanoparticle diameter could be controlled in the range from 2.3 to 10 nm by changing the reaction temperature and time for the precursor. The saturation magnetizations for 10 and 2.3 nm diameter NPs were 192 and 160 emu/g Fe at 5 K. The high M S of the Fe NPs was attributed to lesser amounts of impurities, such as C and O.