Journal Article

Hydrogen-induced tunable remanent polarization in a perovskite nickelate

Yuan, Yifan, Lyu, Xiao, Xu, Xiaoshan, Du, Kai, Bisht, Ravindra S., Wu, Chung-Tse Michael, Ramanathan, Shriram, Ni, Yuanyuan, Patel, Ranjan Kumar, Yu, Haoming, Deng, Sunbin, Kotiuga, Michele, Zhu, Minning, Ye, Peide D., Sadowski, Jerzy T., Zhou, Hua, Al-Mahboob, Abdullah, Cheong, Sang-Wook, Rabe, Karin M., Park, Tae Joon, Saha, Arnob, Sengupta, Abhronil

2024

Overview

Materials with field-tunable polarization are of broad interest to condensed matter sciences and solid-state device technologies. Here, using hydrogen (H) donor doping, we modify the room temperature metallic phase of a perovskite nickelate NdNiO3 into an insulating phase with both metastable dipolar polarization and space-charge polarization. We then demonstrate transient negative differential capacitance in thin film capacitors. The space-charge polarization caused by long-range movement and trapping of protons dominates when the electric field exceeds the threshold value. First-principles calculations suggest the polarization originates from the polar structure created by H doping. We find that polarization decays within ~1 second which is an interesting temporal regime for neuromorphic computing hardware design, and we implement the transient characteristics in a neural network to demonstrate unsupervised learning. These discoveries open new avenues for designing ferroelectric materials and electrets using light-ion doping.

• Publisher: Nature Publishing Group
• Subject: Electrical and electronic engineering / Ferroelectric materials / Ferroelectrics and multiferroics / MATERIALS SCIENCE / Neuromorphic computing / Perovskite nickelate