Enhancement of magnetic anisotropy in mechanically attrited Cr2O3 nanoparticles

► Cr2O3 nanoparticles of diameter in the range 12-24 nm were prepared by mechanical attrition. ► Two magnetization peaks were obtained under Zero-field cooled condition-one at low temperature and the other at high temperature. ► Peaks shifted to high temperatures as the particle size was reduced. ► Above effect was due to an enhancement of the effective anisotropy of the magnetic phase.