Magnetic Properties of γ-Fe2O3 Nanoparticles at the Verge of Nucleation Process

O. MOSCOSO LONDOÑO; M. CARRIÃO; C. COSIO-CASTAÑEDA; V. BILOVOL; R. COHEN; L.C.C. M. NAGAMINE; R. MARTÍNEZ SÁNCHEZ; E. J. LEDE; R MARTINEZ GARCIA; L. M. SOCOLOVSKY

IEEE TRANSACTIONS ON MAGNETICS

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Lugar: New York; Año: 2013

0018-9464

<!-- @page { size: 21cm 29.7cm; margin: 2cm } P { text-indent: 1.25cm; margin-bottom: 0.21cm; color: #00000a; line-height: 115%; text-align: justify; widows: 2; orphans: 2 } P.western { font-family: "Arial", sans-serif; font-size: 11pt; so-language: en-US } P.cjk { font-family: "Times New Roman", serif; font-size: 11pt; so-language: zh-CN } P.ctl { font-family: "Arial", sans-serif; font-size: 11pt; so-language: en-US } A:link { color: #0000ff; text-decoration: underline } A.sdfootnotesym-ctl { font-family: "Times New Roman", serif } -->A low-energy new method based in a one-step synthesis at room temperature produces very small maghemite nanoparticles. The fast neutralization reaction (co-precipitation) of a ferric solution (FeCl3 aqueous) in a basic medium (NH4OH concentrated) produces an intermediate phase, presumably two-line ferrihydrite, that in oxidizing conditions is transformed to maghemite nanoparticles. That “primordial soup” is characterized by small atoms arrangements, that are the base for maghemite tiny crystals. The final product of the reaction was characterized by X-Ray Diffraction, High-Resolution Transmission Electron Microscopy, X-ray Absorption Fine Structure, Mössbauer spectroscopy, and magnetometry