Title :
Unusually high coercivity at room temperature in CoFe/sub 2/O/sub 4/ nanoparticles
Author :
Chinnasamy, C.N. ; Jeyadevan, B. ; Perales-Perez, O. ; Tohji, K. ; Shinoda, K. ; Kasuya, A.
Author_Institution :
Center for Interdisciplinary Res., Tohoku Univ., Sendai, Japan
Abstract :
Summary form only given. Preparing high coercivity CoFe/sub 2/O/sub 4/ nanoparticles suitable for high-density recording is still a challenge. The theoretical values for a random system of spherical, non-interacting single-domain CoFe/sub 2/O/sub 4/ particles with cubic anisotropy have been predicted to be: M/sub s/ (300 K)=80.8 emu/gm, H/sub c/(300 K)=5.3 kOe and M/sub r//M/sub s/=0.83. Here, for the first time, we report the synthesis of CoFe/sub 2/O/sub 4/ nanoparticles of about 40 nm with unusual high coercivity of 4.3 kOe at room temperature (RT).
Keywords :
cobalt compounds; coercive force; ferrites; magnetic particles; materials preparation; nanoparticles; particle size; 300 K; 40 nm; CoFe/sub 2/O/sub 4/; CoFe/sub 2/O/sub 4/ nanoparticles; cubic anisotropy; high coercivity; high-density recording; room temperature; spherical noninteracting single-domain particles; Anisotropic magnetoresistance; Coercive force; Grain size; Magnetic anisotropy; Magnetic properties; Nanoparticles; Reluctance motors; Temperature; Torque; X-ray scattering;
Conference_Titel :
Magnetics Conference, 2002. INTERMAG Europe 2002. Digest of Technical Papers. 2002 IEEE International
Conference_Location :
Amsterdam, The Netherlands
Print_ISBN :
0-7803-7365-0
DOI :
10.1109/INTMAG.2002.1001492
