Employing dibenzo-24-crown-8-ether (DB24C8) as a phase-transfer catalyst, monodispersed fluorescent lanthanon-doped magnetic FePt:RE (RE = Eu, Dy, and Ce) nanoparticles about 3 urn in size were synthesized through the reduction of H2PtCl6 center dot 6H(2)O, Fe-2(C2O4)(3)center dot 5H(2)O, and RE(NO3)(3) (RE = Eu, Dy, and Cc) by propylene glycol using oleic acid as the stabilizer in the solvent-thermal system. The conversion of the as-synthesized chemically disordered fcc FePt:RE nanoparticles to a chemically ordered L1(0) structure occurred after annealing treatment at 873 K, and was simultaneously accompanied by a coercivity increase. It is interesting that the amorphous formation trend is strengthened in an europium-doped FePt:Eu alloy accompanied by enhancement of the coercive force. Its thermal stability indicated that the addition of europium can inhibit the phase transformation. Moreover, the optical measurement results proved that FePt:Dy alloy nanoparticles have fluorescent properties. (C) 2008 Elsevier Inc. All rights reserved.