Title :
Control of magnetic behavior in Fe3O4 nanostructures
Author :
Ko, Seung Pil ; Soh, Joon-Young ; Kim, Young Keun
Author_Institution :
Dept. of Mater. Sci. & Eng., Korea Univ., Seoul, South Korea
Abstract :
Hexagonally well-ordered nanoporous anodized aluminum oxide (AAO) templates were synthesized by electrochemical method. Then, magnetite (Fe3O4) nanoparticles of 8-15-nm diameter were filled in the pores of the AAO template, and then the morphology and magnetic properties were characterized. Vibrating sample magnetometer measurement indicated that the nanoparticles inside AAO showed superparamagnetic behavior at as-filled state. But after annealing at 600°C for 2 hr, the nanostructure (i.e., an assembly of nanoparticles) exhibited coercivity of 80 Oe. Superconducting quantum interference measurement device data showed that after annealing the blocking temperature was above 300 K. Thus, the annealed magnetite nanostructures possessed ferrimagnetism.
Keywords :
SQUID magnetometers; annealing; coercive force; ferrimagnetism; iron compounds; nanoparticles; nanoporous materials; superparamagnetism; 2 h; 600 C; 8 to 15 nm; Fe3O4; electrochemical synthesis; ferrimagnetism; magnetic behavior control; magnetic property; magnetite nanoparticles; magnetometer measurement; morphology; nanoporous anodized aluminum oxide; nanostructures; superconducting quantum interference measurement; superparamagnetic behavior; Aluminum oxide; Annealing; Iron; Magnetic properties; Morphology; Nanoparticles; Nanoporous materials; Nanoscale devices; SQUID magnetometers; Superconducting magnets; Anodized aluminum oxide membrane; magnetite; nanoparticle arrays; nanostructures;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2005.854907
