Improved properties of BaFe12O19 prepared by ammonium nitrate melt technique and washed in HCl
JOURNAL OF ALLOYS AND COMPOUNDS, vol.422, pp.276-278, 2006 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 422
- Publication Date: 2006
- Doi Number: 10.1016/j.jallcom.2005.11.043
- Journal Name: JOURNAL OF ALLOYS AND COMPOUNDS
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.276-278
- Keywords: permanent magnets, chemical synthesis, magnetization, magnetic measurements, barium ferrites, MAGNETIC-PROPERTIES, SOL-GEL, NANOPARTICLES, STOICHIOMETRY
- Middle East Technical University Affiliated: No
Abstract
We have synthesized BaFe12O19 samples by ammonium nitrate melt technique (ANMT) at temperatures from 850 to 1200 degrees C. Calcinations at 850-1000 degrees C yield single domain grains having reasonably high coercive fields up to 4500 Oe. Higher temperature calcinations decrease the coercive fields due to multi-domain grain growth. Washing the samples in HCl is effective to reduce the impurities, especially the antiferromagnetic BaFe2O4. HCl-washing increases magnetization by about 50%; the saturation magnetization increases from 36-45 to 58-62 emu/g and the residual magnetization from 21-26 to 32-34 emu/g. (c) 2005 Elsevier B.V. All rights reserved.