title: Effect of sintered grain growth on chemical ordering in binary FePt/Cu nanoparticle arrays.
abstract: Recent studies have shown a strong correlation between grain growth and chemical ordering in chemically synthesized FePt nanoparticles. In order to study this effect, we have prepared a series of samples in which 3.5 nm FePt nanoparticles are dispersed in a matrix of Cu nanoparticles. The samples were annealed at 600 degrees C and at 800 degrees C. Grain size was determined by XRD Scherrer analysis and time-dependent remanent coercivity measurements were made to determine the intrinsic remanent coercivity, Hcr0. For samples annealed at 600 degrees C, Hcr0 increases strongly with grain size up to approximately 5 nm and increases weakly with additional grain growth. By contrast, after annealing at 800 degrees C, Hcr0 appears nearly independent of grain size. The results suggest that isolated 3.5 nm FePt nanoparticles can be weakly ordered when annealed at 600 degrees C and sintering is necessary for significant chemical ordering.
authors.affiliation: Center for Materials for Information Technology, The University of Alabama, Tuscaloosa 35487, USA.
authors.forename: Shifan
authors.initials: S
authors.lastname: Shi
authors.forename: Shishou
authors.initials: S
authors.lastname: Kang
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Jia
authors.forename: David E
authors.initials: DE
authors.lastname: Nikles
authors.forename: J W
authors.initials: JW
authors.lastname: Harrell
authors.forename: M
authors.initials: M
authors.lastname: Shamsuzzoha
mesh_terms: D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D006358:Hot Temperature; D007501:Iron / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D007854:Lead; D003300:Copper; D007501:Iron