• Chang, Xue
• Fedorova, Natalya S.
• Chen, Long-Qing
• Peng, Ren-Ci
• Fernandez, Abel
• Zhang, Hongrui
• Pesquera, David
• Huang, Xiaoxi
• Íñiguez-González, Jorge
• Das, Sujit
• Ramamoorthy, Ramesh
• Nikonov, Dmitri
• Parsonnet, Eric
• Cheng, Xiaoxing
• Young, Ian

Abstract

<jats:title>Abstract</jats:title><jats:p>Reducing the switching energy of ferroelectric thin films remains an important goal in the pursuit of ultralow-power ferroelectric memory and logic devices. Here, we elucidate the fundamental role of lattice dynamics in ferroelectric switching by studying both freestanding bismuth ferrite (BiFeO<jats:sub>3</jats:sub>) membranes and films clamped to a substrate. We observe a distinct evolution of the ferroelectric domain pattern, from striped, 71° ferroelastic domains (spacing of ~100 nm) in clamped BiFeO<jats:sub>3</jats:sub>films, to large (10’s of micrometers) 180° domains in freestanding films. By removing the constraints imposed by mechanical clamping from the substrate, we can realize a ~40% reduction of the switching voltage and a consequent ~60% improvement in the switching speed. Our findings highlight the importance of a dynamic clamping process occurring during switching, which impacts strain, ferroelectric, and ferrodistortive order parameters and plays a critical role in setting the energetics and dynamics of ferroelectric switching.</jats:p>

Topics

• thin film
• Bismuth