David J. Sellmyer

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Core-shell structures of oxide nanoparticles having a high dielectric constant, and organic shells with large breakdown field are attractive candidates for large electrical energy storage applications. A high growth temperature, however, is required to obtain the dielectric oxide nanoparticles, which affects the process of core-shell formation and also(More)
The embedding of oxide nanoparticles in polymer matrices produces a greatly enhanced dielectric response by combining the high dielectric strength and low loss of suitable host polymers with the high electric polarizability of nanoparticles. The fabrication of oxide-polymer nanocomposites with well-controlled distributions of nanoparticles is, however,(More)
Rare-earth transition-metal (R-TM) alloys show superior permanent magnetic properties in the bulk, but the synthesis and application of R-TM nanoparticles remains a challenge due to the requirement of high-temperature annealing above about 800 °C for alloy formation and subsequent crystalline ordering. Here we report a single-step method to produce highly(More)
This study presents the structural and magnetic properties of melt-spun , , and alloys. Appreciable permanent-magnet properties with a magnetocrystalline anisotropy of about 9.6–16.5 , a magnetic polarization –10.6 kG, and coercivities –3.0 kOe were obtained by varying the composition of these alloys. Structural analysis reveals that the positions of x-ray(More)
We report a simple, yet general, approach to monodisperse MPt (M = Fe, Co, Ni, Cu, Zn) nanoparticles (NPs) by coreduction of M(acac)2 and Pt(acac)2 (acac = acetylacetonate) with oleylamine at 300 °C. In the current reaction condition, oleylamine serves as the reducing agent, surfactant, and solvent. As an example, we describe in details the synthesis of 9.5(More)
Magnetic nanoparticles smaller than ~15 nm in diameter and with high magnetocrystalline anisotropies K1 ≥ 1 MJ m can be used as building blocks for next-generation permanent magnets. Advances in processing steps are discussed, such as self-assembly, alignment of the easy axes and appropriate nanostructuring that will enable the fabrication of densely packed(More)
We report a one-pot synthesis of urchin-like FePd-Fe3O4 nanocomposites, spherical clusters of FePd nanoparticles (NPs) with spikes of Fe3O4 nanorods (NRs), via controlled thermal decomposition of Fe(CO)5 and reduction of Pd(acac)2. The FePd NPs with sizes between 6 and 9 nm self-aggregate into 60 nm superparticles (SPs), and Fe3O4 NRs grow on the surface of(More)