抄録
Differences in the lattice parameters of hematite, ilmenite and magnetite are responsible for lattice mismatch across the boundaries of magnetite-ilmenite and hematite-ilmenite lamellae. Most of this mismatch is relieved by periodic edge dislocations, the remainder by constant strain of the lattice. The periodic stress field produced by the dislocations and the constant stress due to crystal strain are calculated for both types of lamellae. A model based on magnetostrictive control of magnetization can account for the coercivities of hematite lamellae in ilmenite. The model predicts that the coercive force of such a lamella should be inversely proportional to the square root of the lamella thickness, and calculated coercivities agree well with observed values. High coercivities associated with magnetite-ilmenite lamellae are probably due to single domain effects, since they cannot be accounted for by magnetostrictive control of any type.
