Synthesis, characterisation and magnetic studies on nanocrystalline Co0.2Zn0.8Fe2O4

Nanocrystalline Co0.2Zn0.8Fe2O4 have been synthesised by the co-precipitation method. XRD shows that the spinel ferrite is formed after sintering the sample at 393 K. Nanoparticles with average particle size of 5-65 nm were obtained by sintering the samples between 393 and 1173 K. FTIR show that spinel ferrites prepared by precipitation method retain some hydroxyl groups, which are not removed completely by sintering at temperatures less than or equal to873 K. DTA/TG measurements show that between 573 and 823 K spinel is formed and a small weight loss above 873 K is due to removal of hydroxyl. Saturation magnetization of the samples increase with increasing average particle size upto 11 nm and for samples with particle size >11 nm, the saturation magnetization decreases with increasing particle size. This is due to a change in cation distribution with change in particle size. (C) 2003 Elsevier Ltd. All rights reserved.