| 摘要 |
923,991. Magnetic compositions. NIPPON ELECTRIC CO. Ltd. Jan. 25, 1960 [Feb. 4, 1959], No. 2719/60. Class 38 (2). A manganese-zinc ferrite includes 0.05-0.3% by weight CaO and 0.005-0.035% by weight SiO 2 to decrease losses. In a series of tests using very pure oxides there was added to a mixture of 54 mol. per cent Fe 2 O 3 , 35 mol. per cent MnO and 11 mol. per cent ZnO quantities of CaO from 0.1 to 0.7% by weight and of SiO 2 from 0.01-0.07% by weight. The mixture was sintered at 1200‹ C. in pure N 2 for 4 hours. In other examples the main constituents were : 53.5 mol. per cent Fe 2 O 3 , 30 mol. per cent MnO, 16.5 mol. per cent ZnO, and 54.1 mol. per cent Fe 2 O 3 , 35 mol. per cent MnO, 10.9 mol. per cent ZnO. A N 2 /O 2 atmosphere may be used and TiO, A1 2 O 3 or SnO may be added to improve the temperature coefficient of permeability. The Specification discloses a list of metals whose oxides have been used as single additions to MnZn ferrite. The CaO and SiO 2 may be added as compounds yielding the oxides at the final stage. |
