Some vibrational and magnetic properties of an interface and a planar defect in the elastic approximation

Abstract
In the frame of an elastic approximation, the mean-square displacements of atoms for an interface between two different crystals or for a planar defect are reported as well as the interaction of an isotopic impurity with the interface or the planar defect. The interface laws are different in nature from those of the planar-defect. The low-temperature specific heat of an interface between two Heisenberg ferromagnets is also reported as well as the mean spin deviation from their maximum values.