Structures that simultaneously combine electrical polarization and magnetization may be used in memory storage devices [1.2]. Unfortunately, these properties are weakly manifested in a single material. This is due to the incompatibility of chemical and electronic bonds. An effective combination of the properties of multiferroics may be achieved by creating multilayer heterostructures in which each layer has the necessary properties [3], or by decreasing spatial symmetry through stress engineering.     Roentgenographic, nonlinear-optic research was conducted, in conjunction with research of the surface using electron microscopy of a series of heterostructures with even and odd numbers of monolayers YFeO3 and LaFeO3 on a base of DyScO3. The total thickness of the stressed multilayer was equal to 160 nm.   A symetrical analysis of azimuthal dependencies of generation of the second optical harmonic showed that the nonlinear optical signal for the film LaFeO3 is determined by the magnetic dipole contribution.  The magnitude of the polarization signal was observed to be dependent on the number of monolayers: the maximum signal was recorded in heterostructures with an odd number of monolayers. The magnetically-induced generation of the second optical harmonic that is observed in the structures likewise demonstrates a dependence on the number of monolayers. Likewise, an even number of monolayers increases the coercitive field. It has been shown that when photons have an energy of 1.41 eV there occurs a resonant amplification of the magnetic dipolar contribution of generation of the second optical harmonic (2.82 eV).   Thus, by altering the quantity of layers we can change and thereby improve the properties of the structure.