Surface magnetism of real iron borate monocrystals

A theory of the surface magnetism of iron borate, FeBO3, allowing for the non-ideality of the crystal structure of the near-surface layer is constructed. Since the magnetizing field of a near-surface layer appears to be inversely proportional to the tenth power of the crystal lattice parameter, the influence of the non-ideality on the surface magnetism should be substantial. The suggested models of reconstruction make it possible to describe experiments if the magnitude of the deformations is in agreement with literature data. The theoretical dependence of the value of the surface anisotropy on the concentration of point defects in a near-surface layer of the crystal is also established.