Improvements in or relating to ferromagnetic manganese-magnesium-zinc ferrite bodies

摘要

1,128,639. Magnetic compositions. SIEMENS A.G. 28 Sept., 1966 [30 Sept., 1965], No. 43207/66. Heading H1H. A sintered ferrite body has the composition in mole per cent: 33% to less than 50% Fe 2 O 3 20-25% MnO 22-32% MgO 2-10% ZnO 0À5-5% Li 2 O The body may also contain 0À5-5 mole per cent CaO, TiO 2 , or SnO 2 . It may be prepared by mixing a Mn-Mg-Zn ferrite with the other oxides or percursors, or by mixing the separate oxides or percursors. Li 2 CO 3 , may be used. The starting materials may be mixed in alcohol, dried, mixed with a binder, pressed to form annular cores, heated at À02 mm. Hg to 1180‹ C. then sintered in air, and cooled to room temperature over ¢ hr. at 100 mm. Hg. The ferrite has a square hysteresis loop and is used as a store or switching element.