X-ray diffraction, Mossbauer and magnetization measurements have been performed on hematite nanoparticles, prepared by sol-gel method, to study the effect of the mixing tools used in the preparation on their magnetic properties. It has been shown that the mixing tool, i.e. magnetic or mechanical, has a crucial effect on the magnetic behaviors of magnetic nanoparticles. Furthermore, the degree of purity of nitrogen gas used in the preparation process also plays a minor role in magnetic properties of such nanoparticles. (C) 2013 Elsevier B. V. All rights reserved.