Journal of Applied Physics · 2011 · 17 citations · 6 references
Natural SciencesChemistryMaterials ScienceMagnetic MaterialsNanomaterialsNanotechnologyInorganic NanoparticlesIron OxidesMagnetic CharacterizationMagnetic NanomaterialsMagnetic OxidesMetal Oxide NanomaterialsCore-shell Magnetic NanostructuresFerrite NanoparticlesIron Oxide NanoparticlesMagnetic NanoparticlesMagnetic Oxide NanoparticlesNanoparticlesNéel RelaxationTemperature Dependence
We report on the successful preparation and characterization of fluorescent magnetic core∕shell Fe(3)O(4)∕ZnSe nanoparticles (NPs) with a spherical shape by organometallic synthesis. The 7 nm core∕3 nm shell NPs show good magnetic and photoluminescence (PL) responses. The observed PL emission∕excitation spectra are shifted to shorter wavelengths, compared to a reference ZnSe NP sample. A dramatic reduction of PL quantum yield is also observed. The temperature dependence of the magnetization for the core∕shell NPs shows the characteristic features of two coexisting and interacting magnetic (Fe(3)O(4)) and nonmagnetic (ZnSe) phases. Compared to a reference Fe(3)O(4) NP sample, the room-temperature Néel relaxation time in core∕shell NPs is three times longer.
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Shape and Phase Control of Colloidal ZnSe Nanocrystals
P. Davide Cozzoli, Liberato Manna, Maria Lucia Curri et al. · Chemistry of Materials · 2005 · 233 citations