Ferroelectric capped magnetization in multiferroic PZT/LSMO tunnel junctions

摘要

Self-poled ultra-thin ferroelectric PbZr_(0.52)Ti_(0.48_O_3 (PZT) (5 and 7 nm) films have been grown by pulsed laser deposition technique on ferromagnetic La_(0.67)Sr_(0.33)MnO_3 (LSMO) (30 nm) to check the effect of polar capping on magnetization for ferroelectric tunnel junction devices. PZT/LSMO heterostructures with thick polar PZT (7nm) 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 Mn~(3+)/Mn~(4+) ion ratio in the LSMO with 7 nm polar capping.