Origin of Interstitial Doping Induced Coercive Field Reduction in Ferroelectric Hafnia

Fuente: arXiv
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Main Authors: Zhu, Tianyuan, Ma, Liyang, Duan, Xu, Liu, Shi
Format: Preprint
Published: 2024
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author Zhu, Tianyuan
Ma, Liyang
Duan, Xu
Liu, Shi
author_facet Zhu, Tianyuan
Ma, Liyang
Duan, Xu
Liu, Shi
contents Hafnia-based ferroelectrics hold promise for nonvolatile ferroelectric memory devices. However, the high coercive field required for polarization switching remains a prime obstacle to their practical applications. A notable reduction in coercive field has been achieved in ferroelectric Hf(Zr)$_{1+x}$O$_2$ films with interstitial Hf(Zr) dopants [Science 381, 558 (2023)], suggesting a less-explored strategy for coercive field optimization. Supported by density functional theory calculations, we demonstrate the $Pca2_1$ phase, with a moderate concentration of interstitial Hf dopants, serves as a minimal model to explain the experimental observations, rather than the originally assumed rhombohedral phase. Large-scale deep potential molecular dynamics simulations suggest that interstitial defects promote the polarization reversal by facilitating $Pbcn$-like mobile 180$^\circ$ domain walls. A simple pre-poling treatment could reduce the switching field to less than 1 MV/cm and enable switching on a subnanosecond timescale. High-throughput calculations reveal a negative correlation between the switching barrier and dopant size and identify a few promising interstitial dopants for coercive field reduction.
format Preprint
id arxiv_https___arxiv_org_abs_2407_02808
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Origin of Interstitial Doping Induced Coercive Field Reduction in Ferroelectric Hafnia
Zhu, Tianyuan
Ma, Liyang
Duan, Xu
Liu, Shi
Materials Science
Computational Physics
Hafnia-based ferroelectrics hold promise for nonvolatile ferroelectric memory devices. However, the high coercive field required for polarization switching remains a prime obstacle to their practical applications. A notable reduction in coercive field has been achieved in ferroelectric Hf(Zr)$_{1+x}$O$_2$ films with interstitial Hf(Zr) dopants [Science 381, 558 (2023)], suggesting a less-explored strategy for coercive field optimization. Supported by density functional theory calculations, we demonstrate the $Pca2_1$ phase, with a moderate concentration of interstitial Hf dopants, serves as a minimal model to explain the experimental observations, rather than the originally assumed rhombohedral phase. Large-scale deep potential molecular dynamics simulations suggest that interstitial defects promote the polarization reversal by facilitating $Pbcn$-like mobile 180$^\circ$ domain walls. A simple pre-poling treatment could reduce the switching field to less than 1 MV/cm and enable switching on a subnanosecond timescale. High-throughput calculations reveal a negative correlation between the switching barrier and dopant size and identify a few promising interstitial dopants for coercive field reduction.
title Origin of Interstitial Doping Induced Coercive Field Reduction in Ferroelectric Hafnia
topic Materials Science
Computational Physics
url https://arxiv.org/abs/2407.02808