What is antiferromagnetism?

Question

Wikipedia is giving me BS. what does it have to do with hematite

Answer 1

type of magnetism in solids such as manganese oxide (MnO) in which adjacent ions that behave as tiny magnets (in this case manganese ions, Mn2+) spontaneously align themselves at relatively low temperatures into opposite, or antiparallel, arrangements throughout the material so that it exhibits almost no gross external magnetism