Cobalt-ferrite nanoparticles: Structure, cation distributions, and magnetic properties

被引:68
作者
Li, SC
John, VT
O'Connor, C
Harris, V [1 ]
Carpenter, E
机构
[1] USN, Res Lab, Washington, DC 20375 USA
[2] Tulane Univ, Dept Chem Engn, New Orleans, LA 70118 USA
[3] Univ New Orleans, Adv Mat Res Inst, New Orleans, LA 70148 USA
关键词
D O I
10.1063/1.372661
中图分类号
O59 [应用物理学];
学科分类号
摘要
Cobalt-ferrite nanoparticles have been synthesized in water-in-oil microemulsions (reversed micelles) with varying cation composition. The microenvironment provides a template effect that controls the size and particle shape. Transmission electron microscopy reveals that the particles are nanospheres with particle size ranging from 12 to 18 nm. X-ray diffraction results indicate that at low Co2+:Fe2+ ratio (1:10 and 1:5) in the precursor, the particles retain an essentially ferrite structure (gamma-Fe2O3). However, the cobalt-ferrite phase (CoFe2O4) forms upon further increase of the Co2+ content. The materials are found to exhibit superparamagnetism. The blocking temperatures and coercivities are dependent on the Co2+:Fe2+ ratio in the system. (C) 2000 American Institute of Physics. [S0021- 8979(00)77708-5].
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页码:6223 / 6225
页数:3
相关论文
共 10 条
[1]   Atomic structure and magnetic properties of MnFe2O4 nanoparticles produced by reverse micelle synthesis [J].
Carpenter, EE ;
O'Connor, CJ ;
Harris, VG .
JOURNAL OF APPLIED PHYSICS, 1999, 85 (08) :5175-5177
[2]   DIRECT MEASUREMENT OF OCTAHEDRAL AND TETRAHEDRAL SITE ENVIRONMENTS IN NIZN-FERRITES [J].
HARRIS, VG ;
KOON, NC ;
WILLIAMS, CM ;
ZHANG, Q ;
ABE, M ;
KIRKLAND, JP ;
MCKEOWN, DA .
IEEE TRANSACTIONS ON MAGNETICS, 1995, 31 (06) :3473-3475
[3]   SYNTHESIS OF COPPER METALLIC CLUSTERS USING REVERSE MICELLES AS MICROREACTORS [J].
LISIECKI, I ;
PILENI, MP .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1993, 115 (10) :3887-3896
[4]   New syntheses of cobalt ferrite particles in the range 2-5 nm: Comparison of the magnetic properties of the nanosized particles in dispersed fluid or in powder form [J].
Moumen, N ;
Pileni, MP .
CHEMISTRY OF MATERIALS, 1996, 8 (05) :1128-1134
[5]   MAGNETOCHEMISTRY - ADVANCES IN THEORY AND EXPERIMENTATION [J].
OCONNOR, CJ .
PROGRESS IN INORGANIC CHEMISTRY, 1982, 29 :203-283
[6]   PREPARATION OF NANOPARTICLES OF SILVER-HALIDES, SUPERCONDUCTORS AND MAGNETIC-MATERIALS USING WATER-IN-OIL MICROEMULSIONS AS NANO-REACTORS [J].
PILLAI, V ;
KUMAR, P ;
HOU, MJ ;
AYYUB, P ;
SHAH, DO .
ADVANCES IN COLLOID AND INTERFACE SCIENCE, 1995, 55 :241-269
[7]   Synthesis of high-coercivity cobalt ferrite particles using water-in-oil microemulsions [J].
Pillai, V ;
Shah, DO .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1996, 163 (1-2) :243-248
[8]   STRUCTURE AND MAGNETIC-PROPERTIES OF NANOPARTICLES OF BARIUM FERRITE SYNTHESIZED USING MICROEMULSION PROCESSING [J].
PILLAI, V ;
KUMAR, P ;
MULTANI, MS ;
SHAH, DO .
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 1993, 80 (01) :69-75
[9]  
SAYERS DE, 1988, CHEM ANAL, V92, P211
[10]   Magnetic properties of a series of ferrite nanoparticles synthesized in reverse micelles [J].
Seip, CT ;
Carpenter, EE ;
O'Connor, CJ ;
John, VT ;
Li, SC .
IEEE TRANSACTIONS ON MAGNETICS, 1998, 34 (04) :1111-1113