Magnetostriction of Antiferromagnetic Cr2O3 in Strong Magnetic Fields

The magnetostriction of antiferromagnetic Cr2O3 has been measured in a magnetic field directed along the crystal symmetry axis. In the field H c = 60 kOe which corresponds to a spin‐flip transition we have observed jumps in the crystal sizes. The deformation along the symmetry axis is 2.8 × 10−5 and the relative volume change is 2.0 × 10−5. The form of the magnetostriction curves may be accounted for by the dependence of magnetic anisotropy energy on the interatomic distances. The calculation of magnetic dipole interaction in the given crystal provides jump values which are considerably lower than those observed. The contributions to the magnetic anisotropy energy arising from considering the spin‐orbit coupling are assumed to be important for magnetoelastic properties of Cr2O3.