Antiphase Domains and Reverse Thermoremanent Magnetism in Ilmenite-Hematite Minerals

Science  18 Sep 1981:
Vol. 213, Issue 4514, pp. 1372-1374
DOI: 10.1126/science.213.4514.1372


Examination of synthetic ilmenite-hematite samples by transmission electron microscopy has for the first time revealed the presence of well-defined antiphase domains and antiphase domain boundaries in this mineral system. Samples quenched from 1300°C have a high density of domain boundaries, whereas samples quenched from 900°C have a much lower density. Only the high-temperature samples acquire reverse thermoremanent magnetism when cooled in an applied magnetic field. The presence of a high density of domain boundaries seems to be a necessary condition for the acquisition of reverse thermoremanent magnetism.