Lead Ferrite Disc Magnet: 0.15 mol PbO2 to 0.9 mol Iron Oxide, Presintered at 900 °C (Went, Philips 1956, Ex. 17)

A lead ferrite magnet: 0.15 mol lead dioxide to 0.9 mol iron oxide, milled in an iron ball mill, dried at 150 °C, presintered 2 hours at 900 °C, pressed and passed through a 1150 °C furnace in 3 to 5 minutes. Went's rod held 1,420 gauss with a coercive force of 1,830 oersted. Lead compounds are poisonous. Source: J. J. Went, G. W. van Oosterhout and E. W. Gorter (Philips), US 2,762,777 (1956), Example 17. They sintered rods; discs and the magnetising are ours. Picture: ferrite magnets, Omegatron, Wikimedia Commons, CC BY-SA 3.0.