Field evolution of magnetic correlations in ϵ-Co nanoparticle assemblies
Small-angle neutron scattering measurements of Co nanoparticle assemblies reveal three characteristic length scales associated with the interparticle and intraparticle magnetic orders. The first length scale stemming from particle size and separation does not vary with applied field. In contrast, the magnetic correlation length increases from 71±9nm in zero field at 5K to greater than 1000nm in fields larger than 0.2T. The random-field length scale decreases from 37±8nm when H=0to9.1±0.3nm in H=0.2T, and the contribution of this term is less significant in large fields.
Sachan, M., C. Bonnoit, S. A. Majetich, Y. Ijiri, et al. 2008. "Field evolution of magnetic correlations in ϵ-Co nanoparticle assemblies." Applied Physics Letters 92.
Applied Physics Letters
Physics and Astronomy
Nanoparticles, Magnetic nanoparticles, Particle scattering, Transmission electron microscopy, Neutrons