Barium-Lead Ferrite Disc Magnet: 0.35 mol BaCO3 and 0.3 mol PbO2, 1145 °C (Went, Philips 1956, Ex. 32)

A ceramic magnet with both barium and lead: 0.35 mol barium carbonate and 0.3 mol lead dioxide to 3.4 mol iron oxide, milled 15.5 hours, presintered by heating slowly to 900 °C, pressed and passed through a 1145 °C furnace in 4 minutes. Went's rod held 1,785 gauss with a coercive force of 2,840 oersted. Barium and lead compounds are poisonous. Source: J. J. Went, G. W. van Oosterhout and E. W. Gorter (Philips), US 2,762,777 (1956), Example 32. They sintered rods; discs and the magnetising are ours. Picture: ferrite magnets, Omegatron, Wikimedia Commons, CC BY-SA 3.0.