Multiferroics are currently of great interest for applications in microelectronics namely in future data storage and spintronic devices. These materials couple simultaneously ferroelectric and ferromagnetic properties and have potentially different applications resulting from the coupling between their dual order parameters. A true multiferroic material is single phase. However, the known true multiferroic materials possess insufficient coupling between the two phenomena or their magnetoelectric response occurs at temperatures too low to be useful in practical applications. But a tremendous progress in the field of microelectronics can be expected if one is able to design an effective multiferroic material with ideal coupling of the ferromagnetic and ferroelectric properties to suit a particular application. Within this context composite structures are gaining considerable interest and different strategies in terms of materials microstructure have been proposed including horizontal multilayers and vertical heterostructures. In the horizontal multilayer heterostructures, the alternating layers of conventional ferro/ferrimagnetic and ferroelectric phases are grown, while in the vertical heterostructures nanopillars of the ferro/ferrimagnetic phase are embedded in a ferroelectric matrix. The later structures show advantages over the first ones because promote larger interfacial surface area and are intrinsically heteroepitaxial in three dimensions; which is expected to allow a stronger coupling between ferroelectric and ferromagnetic components.