Strontium Ferrite Disc Magnet: Presintered at 1100 °C, 0.1 mol SrCO3 to 0.7 mol Iron Oxide (Went, Philips 1956, Ex. 8)

A strontium ferrite: 0.1 mol strontium carbonate to 0.7 mol iron oxide, dried, milled, presintered 3.5 hours at 1100 °C, bound, formed and passed through a 1280 °C furnace in 10 minutes. Went's rod held 1,535 gauss with a coercive force of 2,800 oersted. Source: J. J. Went, G. W. van Oosterhout and E. W. Gorter (Philips), US 2,762,777 (1956), Example 8. They sintered rods; discs and the magnetising are ours. Picture: ferrite magnets, Omegatron, Wikimedia Commons, CC BY-SA 3.0.