Magnetization of Ultrafine Cadmium Ferrite Particles

Park, Eun-Jung; Park, Eun-Jung

doi:2002.39.1.12

J. Korean Ceram. Soc. > Volume 39(1); 2002 > Article

Journal of the Korean Ceramic Society 2002;39(1): 12.
doi: https://doi.org/10.4191/kcers.2002.39.1.012

Magnetization of Ultrafine Cadmium Ferrite Particles

ABSTRACT

Ultrafine cadmium ferrite particles have been investigated by X-ray diffractometry, transmission electron microscopy and SQUID magnetometry. All peaks of X-ray diffraction patterns are broad, but correspond to a cubic spinel structure with the lattice constant of 8.65 $AA$. The average particle size determined by TEM is 9.7 nm and the size distribution of particles is not normal, but lognormal. The maximal magnetization measured at 5 K was 17.7 emu/g. The experimental data show a transi-tion from a disorder ferrimagnetic phase to a spin-glass phase (i.e. reentrant behavior) with a freezing temperature (T$_$f/) of 30 K. Superparamagnetic behavior of the particles is confirmed by the coincidence of the plots of M vs. H/T for 100 and 300 K.

Key words: Ultrafine particles, Particle size distribution, Magnetization, Superparamagnetism