TY - JOUR
T1 - Magnetic properties of nanoparticles of Cox Fe(3-x) O4 (0.05≤x≤1.6) prepared by combustion reaction
AU - Franco Júnior, Adolfo
AU - Zapf, Vivien
AU - Egan, Paul
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2007
Y1 - 2007
N2 - Nanoparticles of Cox Fe(3-x) O4 with x ranging from 0.05 to 1.6 were synthesized by a combustion reaction method using iron nitrate, cobalt nitrate, and urea as fuel. X-ray diffraction patterns of all systems showed broad peaks consistent with the cubic inverse spinel structure of cobalt ferrite. The absence of extra reflections in the diffraction patterns of as-prepared materials, with x=0.6, 0.8, and 1.0, demonstrates the phase purity. Magnetization measurements show that the saturation magnetization (Ms), coercivity (Hc), and remanent magnetization (Mr) depend on the molar cobalt concentration and the temperature as well. At 4 K, the reduced remanence, Mr Ms, are equal to 0.66 and 0.63 for x=0.8 and 1.0, respectively, indicating that cubic-type magnetic anisotropy is significant in these nanoparticles. These observations are discussed in terms of a model in which it is assumed that each crystallite consists of a ferromagnetic core surrounded by a magnetically disordered shell.
AB - Nanoparticles of Cox Fe(3-x) O4 with x ranging from 0.05 to 1.6 were synthesized by a combustion reaction method using iron nitrate, cobalt nitrate, and urea as fuel. X-ray diffraction patterns of all systems showed broad peaks consistent with the cubic inverse spinel structure of cobalt ferrite. The absence of extra reflections in the diffraction patterns of as-prepared materials, with x=0.6, 0.8, and 1.0, demonstrates the phase purity. Magnetization measurements show that the saturation magnetization (Ms), coercivity (Hc), and remanent magnetization (Mr) depend on the molar cobalt concentration and the temperature as well. At 4 K, the reduced remanence, Mr Ms, are equal to 0.66 and 0.63 for x=0.8 and 1.0, respectively, indicating that cubic-type magnetic anisotropy is significant in these nanoparticles. These observations are discussed in terms of a model in which it is assumed that each crystallite consists of a ferromagnetic core surrounded by a magnetically disordered shell.
UR - http://www.scopus.com/inward/record.url?scp=34248572339&partnerID=8YFLogxK
U2 - 10.1063/1.2711063
DO - 10.1063/1.2711063
M3 - Article
AN - SCOPUS:34248572339
VL - 101
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 9
M1 - 09M506
ER -