Surface Review and Letters · 1996 · 28 citations · 0 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsMagnetic MaterialsNanomaterialsMagnetic CharacterizationMagnetic NanomaterialsMagnetic OxidesMagnetic Properties Of SolidsMagnetism In SolidsSurface MagnetismEffective Coordination NumberIsing ModelIsing Model FormulationMean-field TheoryNeel TemperatureNéel TemperatureUltrafine Particle FormationUltrafine Particles
The effect of the decrease in the coordination number of atoms in surface on the magnetic transition temperature was investigated experimentally and theoretically for CoO ultrafine particles. The decreasing tendency of the Néel temperature T N with decreasing average size was confirmed in the size range from 2.0 to 3.0 nm through the ESR measurement. The similar tendency of T N for size was gained through the calculation of T N in the mean-field theory using the prism model within the Ising thin-film model.