Mater. Charact.

Co- and Ga-doped magnetites were synthesized at room temperature and CoFe(2)O(4) was synthesized at 60 degrees C. They were analyzed by Mossbauer analysis, X-ray diffraction, scan electron microscopy as well as magnetization determination. The information of composition, cation distribution in the spinel structure and the particle size distribution of the products were obtained. Meanwhile, the formation mechanism of Co-doped magnetite was deduced. Two different procedures were used to precipitate CoFe(2)O(4) magnetic particles. One was named normal pH regulation procedure (A) in which alkaline solution was dropped into the mixture solution of metal ions and the other was denoted as reverse pH regulation procedure (B) in which mixture solution of metal ions were dropped into alkaline solution. Particles of uniform size were obtained in procedure A, which resulted from calculated average particle size and Mossbauer analysis. A comparative original method for investigating the magnetic nanoparticle size distribution was developed. (C) 2008 Elsevier Inc. All rights reserved.Co- and Ga-doped magnetites were synthesized at room temperature and CoFe(2)O(4) was synthesized at 60 degrees C. They were analyzed by Mossbauer analysis, X-ray diffraction, scan electron microscopy as well as magnetization determination. The information of composition, cation distribution in the spinel structure and the particle size distribution of the products were obtained. Meanwhile, the formation mechanism of Co-doped magnetite was deduced. Two different procedures were used to precipitate CoFe(2)O(4) magnetic particles. One was named normal pH regulation procedure (A) in which alkaline solution was dropped into the mixture solution of metal ions and the other was denoted as reverse pH regulation procedure (B) in which mixture solution of metal ions were dropped into alkaline solution. Particles of uniform size were obtained in procedure A, which resulted from calculated average particle size and Mossbauer analysis. A comparative original method for investigating the magnetic nanoparticle size distribution was developed. (C) 2008 Elsevier Inc. All rights reserved