Optical Second-Harmonic Polarimetry on Hf0.5Zr0.5O2/La0.67Sr0.33MnO3 Interfaces

The interface-induced second-harmonic generation from ferroelectric hafnium-zirconium oxide (Hf0.5Zr0.5O2) epitaxial thin films, buffered with a La0.67Sr0.33MnO3 bottom electrode, is analyzed as a function of input and output polarization angles and the azimuthal angle of the sample for several film thicknesses. It is shown that the signal is generated mainly from the buffer side of the interface, rather than from the ferroelectric side. However, the ferroelectric film affects significantly the nonlinear optical properties of the underlying ferromagnetic buffer electrode. Several mechanisms accounting for these observations are discussed, from oxygen migration, to an electrostatic effect, including a possible modulation of the La0.67Sr0.33MnO3 magnetization by the upper ferroelectric film.