  Self-poled ultra-thin ferroelectric PbZr0.52Ti0.48O3 (PZT) (5 and 7 nm) films
have been grown by pulsed laser deposition technique on ferromagnetic
La0.67Sr0.33MnO3 (LSMO) (30 nm) to check the effect of polar capping on
magnetization for ferroelectric tunnel junction (FTJ) devices. PZT/LSMO
heterostructures with thick polar PZT (7 nm) capping show nearly 100%
enhancement in magnetization compared with thin polar PZT (5 nm) films,
probably due to excess hole transfer from the ferroelectric to the
ferromagnetic layers. Core-level X-ray photoelectron spectroscopy studies
revealed the presence of larger Mn 3s exchange splitting and higher Mn3+/Mn4+
ion ratio in the LMSO with 7 nm polar capping.
