  We investigate in the framework of Landau theory the distortion of the strain
fields at the interface of two dissimilar ferroelastic oxides that undergo a
structural cubic-to-tetragonal phase transition. Simple analytical solutions
are derived for the dilatational and the order parameter strains that are
globally valid over the whole of the heterostructure. The solutions reveal that
the dilatational strain exhibits compression close to the interface which may
in turn affect the electronic properties in that region.
