Mossbauer evaluation of cobalt ferrite nanoparticles synthesized by forced hydrolysis

Spinel cobalt ferrite in the form of nearly spherical particles, having a narrow range of particle size around 7.6 nm, was produced by forced hydrolysis. Between the magnetization blocking temperature of 180 K and the Mossbauer blocking temperature of 270 K, the magnetic anisotropy energy decreases rapidly with temperature. The occupancy of the octahedral sites by only half of the Co2+ cations may have weakened the crystalline anisotropy. Significant spin canting was also observed at these sites. (C) 2005 American Institute of Physics.