Open AccessMethod for fabricating Fe3O4 nanoparticles using H2O2 and its comparison with coprecipitation method
Author(s) -
Fashen Li,
Tao Wang,
Ying Wang
Publication year - 2005
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.54.3100
Subject(s) - coprecipitation , superparamagnetism , materials science , spinel , hyperfine structure , squid , analytical chemistry (journal) , magnetization , nanoparticle , magnetometer , transmission electron microscopy , nuclear magnetic resonance , nanotechnology , magnetic field , inorganic chemistry , chemistry , physics , metallurgy , ecology , chromatography , quantum mechanics , biology
Fe34 nanoparticles were successfully synthesized from an aqueous Fe (OH)2 colloid under nearly neutral condition by oxidizing it with H22. The m orphology, structure, and magnetic properties were characterized and measured by transmission electron microscopy (TEM), x-ray diffraction (XRD), vibrating sam ple magnetometer, and superconducting quantum interference devices (SQUID). The TEM image shows that the sample consists of well-dispersed spherical particles with diameter about 18nm, and has a cubic spinel structure according to XRD. The mssbauer spectrum at room temperature is fitted using two sextet spectrum cor responding to Fe ions at A site and B site, and the results show that th e hyperfine field of the sample is a little smaller than that of bulk value, and crystalline defects exist in the sample. The saturation magnetization of the sa mple fabricated by using H22 is 67×10-3A·m 2/g, and the Ver wey transition was observed at 20K, but the magnetization of the sample fabricat ed by coprecipitation is only 46×10-3A·m2/g when the app lied field is 1 Tesla, and the Verwey transition was not observed in our temperature range of measurement. In addition, the superparamagnetic blocking temperature of the s ample fabricated by coprecipitation was observed at 178K.