| 摘要 |
1,086,406. Magnetic compositions. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. May 6, 1966 [May 10, 1965], No. 20145/66. Heading H1H. A ferrimagnetic material has the composition where M<SP>II</SP> is one or more of Mn, Fe, Ni, Cu, Zn, Mg, or the complex (Li<SP>I</SP> + Fe<SP>III</SP>)/2, and where 1#a#0, 0À6#b#0, 0À3#c#O, 2#d#0À5, and 2#e#0À1. It may be prepared from the component oxides, or oxide yielding compounds, e.g. carbonate, or compounds containing at least 2 of the oxides. The mixture may be ground, e.g. in alcohol, dried, presintered and ground one or more times, shaped with or without a binder, and sintered. Sintering may be effected at 1000-1450‹ C. in air or O 2 , in the presence of silicates or fluorides. After final grinding, the material may be orientated in a rotating magnetic field, and compressed in the orientated state. Alternatively, the initial mixture may be melted, and single crystals grown. The product is similar in crystal structure and properties to that of Specification 833,053. |
