Fe₃O₄/CdSe/ZnS magnetic fluorescent bifunctional nanocomposites

Fe 3 O 4 /CdSe/ZnS magnetic fluorescent bifunctional nanocomposites were obtained by depositing heterogeneous semiconductor on magnetic nanoparticles.The structure and properties of the Fe 3 O 4 /CdSe/ZnS nanocomposites were fully characterized by TEM, XPS, XRD, SQUID and PL.The results indicate that the Fe 3 O 4 /CdSe/ZnS nanocomposites are superparamagnetic and are about 8 nm in size.The quantum yield of the nanocomposites increases from 2-3% in Fe 3 O 4 /CdSe to 10-15% in Fe 3 O 4 /CdSe/ZnS, together with a red shift of both the absorption peak and PL band.The increase of quantum yield is due to the passivation of the surface of magnetic-CdSe nanocomposites with a ZnS layer.