| 摘要 |
668,700. Magnetic compositions. STEATITE RESEARCH CORPORATION. May 10, 1950 [May 26, 1949], No. 11667/50. Class 38 (ii). Magnetic mixed ferrite compositions suitable for use at frequencies up to 10 Mc/sec., having Curie points of at least 250‹ C. initial permeabilities 200-350, saturation flux-densities at least 3750 and temperature coefficients of 25- 35 per cent (measured on a toroid) between room temperature and 125‹ C., comprise the following materials within the stated mol. proportions: MgO (0.05-0.15); MnO (0.2- 0.4); ZnO (0.3-0.4); NiO (0.15-0.4); Fe 2 O 3 (about 1.0). The constituents may be added as oxides or as compounds which become oxides during firing. The components are ground, mixed with water optionally containing plasticizers such as emulsified waxes, moulded, fired at Seger cones 7-10 and cooled in air. |
