Applied Physics Letters · 2009 · 32 citations · 26 references
Natural SciencesMaterials EngineeringMaterials ScienceMagnetic MaterialsNanomaterialsNanotechnologyFerrimagnetic MaterialsInorganic NanoparticlesMagnetic NanomaterialsMagnetic OxidesMetal Oxide NanomaterialsNanoparticle SynthesisCoprecipitationCoprecipitation SynthesisFerrimagnetic NanoparticlesFerrite NanoparticlesFerritesMagnetic NanoparticlesNeel TemperatureNéel Temperature
The tuning of Néel temperature by greater than 100 K in nanoparticle Mn-ferrite was demonstrated by a growth-rate-induced cation inversion. Mn-ferrite nanoparticles, having diameters from 4 to 50 nm, were synthesized via coprecipitation synthesis. The Néel temperature (TN) increased inversely to the cation inversion parameter, δ (i.e., defined as (Mn1−δFeδ)tet[MnδFe2−δ]octO4). Concomitantly, TN increased with increased particle growth rate and particle size. These results unambiguously establish cation inversion as the dominant mechanism in modifying the superexchange leading to enhanced TN. The ability to tailor TN enables greater flexibility in applying nanoparticle ferrites in emerging technologies.
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Chemically prepared magnetic nanoparticles
Matthew A. Willard, Lynn K. Kurihara, Everett E. Carpenter et al. · International Materials Reviews · 2004 · 523 citations