Barium-Strontium Ferrite Disc Magnet: 0.5 mol BaCO3, 0.5 mol SrCO3, 1260 °C (Went, Philips 1956, Ex. 28)

A ceramic magnet with both barium and strontium: 0.5 mol barium carbonate and 0.5 mol strontium carbonate to 3 mol iron oxide, milled 15 hours, pressed and passed through a 1260 °C furnace in 20 minutes. Went's rod held 1,665 gauss with a coercive force of 3,235 oersted. Source: J. J. Went, G. W. van Oosterhout and E. W. Gorter (Philips), US 2,762,777 (1956), Example 28. They sintered rods; discs and the magnetising are ours. Picture: ferrite magnets, Omegatron, Wikimedia Commons, CC BY-SA 3.0.