Ferrite Toroid Core: Nickel-Zinc Ferrite Given a Further Oxygen Treatment (Snoek 1948, Ex. IV)

Snoek's nickel-zinc ferrite ring (Example IV, initial permeability 560), given a further 12 hours at 1000 °C and 20 hours at 750 °C in oxygen. Unlike his magnesium-zinc core, its losses did not change. Nickel oxide dust is a cancer hazard: respirator when milling. Source: J. L. Snoek, US 2,452,529 (Philips, 1948), Example IV. Picture: our diagram.