caa a22 4500 445827661 CHVBK 20180317145304.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s10854-011-0365-2 doi (NATIONALLICENCE)springer-10.1007/s10854-011-0365-2 A novel approach for synthesis of M-type hexaferrites nanopowders via the co-precipitation method [Elektronische Daten] [M. Rashad, I. Ibrahim] M-type hexaferrites; barium hexaferrite BaFe12O19 and strontium hexaferrite SrFe12O19 powders have been successfully prepared via the co-precipitation method using 5M sodium carbonate solution as alkali. Effects of the molar ratio and the annealing temperature on the crystal structure, crystallite size, microstructure and the magnetic properties of the produced powders were systematically studied. The results indicated that a single phase of barium hexaferrite was obtained at Fe3+/Ba2+ molar ratio 12 annealed at 800-1,200°C for 2h whereas the orthorhombic barium iron oxide BaFe2O4 phase was formed as a impurity phase with barium M-type ferrite at Fe3+/Ba2+ molar ratio 8. On the other hand, a single phase of strontium hexaferrite was produced with the Fe3+/Sr2+ molar ratio to 12 at the different annealing temperatures from 800 to 1,200°C for 2h whereas the orthorhombic strontium iron oxide Sr4Fe6O13 phase was formed as a secondary phase with SrFe12O19 phase at Fe3+/Sr2+ molar ratio of 9.23. The crystallite sizes of the produced nanopowders were increased with increasing the annealing temperature and the molar ratios. The microstructure of the produced single phase M-type ferrites powders displayed as a hexagonal-platelet like structure. A saturation magnetization (53.8emu/g) was achieved for the pure barium hexaferrite phase formed at low temperature 800°C for 2h. On the other hand, a higher saturation magnetization value (M s=85.4emu/g) was obtained for the strontium hexaferrite powders from the precipitated precursors synthesized at Fe3+/Sr2+ molar ratio 12 and thermally treated at 1,000°C for 2h. Springer Science+Business Media, LLC, 2011 Rashad M. Central Metallurgical Research and Development Institute (CMRDI), Helwan, P.O. Box: 87, Cairo, Egypt aut Ibrahim I. Central Metallurgical Research and Development Institute (CMRDI), Helwan, P.O. Box: 87, Cairo, Egypt aut Journal of Materials Science: Materials in Electronics Springer US; http://www.springer-ny.com 22/12(2011-12-01), 1796-1803 0957-4522 22:12<1796 2011 22 10854 https://doi.org/10.1007/s10854-011-0365-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10854-011-0365-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rashad M. Central Metallurgical Research and Development Institute (CMRDI), Helwan, P.O. Box: 87, Cairo, Egypt aut NATIONALLICENCE 700 1- Ibrahim I. Central Metallurgical Research and Development Institute (CMRDI), Helwan, P.O. Box: 87, Cairo, Egypt aut NATIONALLICENCE 773 0- Journal of Materials Science: Materials in Electronics Springer US; http://www.springer-ny.com 22/12(2011-12-01), 1796-1803 0957-4522 22:12<1796 2011 22 10854 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer