Ferroelectricity and ferromagnetism in $(Pb, La)(Ca, Ti)O3–La0.67Sr0.33MnOx$ multilayers

Multilayer ferroelectric and ferromagnetic thin films were fabricated with the following composition and structure: $La0.67Sr0.33MnOx/(Pb, La)(Ca, Ti)O3 (LSMO/PLCT)$ and $(Pb, La)(Ca, Ti)O3/La0.67Sr0.33MnOx$ (PLCT/LSMO), with an intention of creating a device of new concept. The films were fabricated using metalorganic deposition. The LSMO/PLCT structured films exhibit the ferroelectric properties while the PLCT/LSMO structured films exhibit the ferromagnetic properties. Compared with the PLCT/Pt structure, the capacitance-frequency and tan δ-frequency properties of the LSMO/PLCT structure are degraded. The magnetoresistance of the PLCT/LSMO structure was measured and the results show that the metal-insulator transition temperature is lower than that of the $LSMO/SiO2/Si$ structure. Furthermore, the magnetoresistance at 77 K and at the transition temperature for the PLCT/LSMO structure is higher than that of the $LSMO/SiO2/Si$ structure. These effects can be explained by the piezoelectricity of the PLCT film deposited on the LSMO layer. In addition, these effects demonstrate that the ferromagnetic properties can be controlled by the ferroelectric properties of the multilayer films.