Ferroelectric Capped Magnetization in Multiferroic PZT/LSMO Tunnel Junctions

TL;DR

This study demonstrates that ferroelectric capping significantly enhances magnetization in PZT/LSMO tunnel junctions, with thicker PZT layers leading to nearly double the magnetization due to charge transfer effects.

Contribution

It reveals the impact of ferroelectric layer thickness on magnetization enhancement in multiferroic tunnel junctions, a novel insight for device engineering.

Findings

Nearly 100% magnetization increase with 7 nm PZT capping

Charge transfer from ferroelectric to ferromagnetic layers influences magnetization

X-ray studies confirm changes in Mn ion ratios and exchange splitting

Abstract

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.