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Title: Ferroelectricity and tunneling electroresistance effect in asymmetric ferroelectric tunnel junctions

Abstract

We report the investigation on the ferroelectricity and tunneling electroresistance (TER) effect in PbTiO{sub 3} (PTO)-based ferroelectric tunnel junctions (FTJs) using first-principles calculations. For symmetric FTJs, we have calculated the average polarizations of PTO film and effective screening lengths of different metal electrodes for a number of FTJs, which is useful for experimental research. For asymmetric FTJs, significant asymmetric ferroelectric displacements in PTO film are observed, which is attributed to the intrinsic field generated by the two dissimilar electrodes. Moreover, by performing quantum transport calculations on those asymmetric FTJs, a sizable TER effect is observed. It is found that the asymmetry of ferroelectric displacements in PTO barrier, which is determined by the difference of work functions of the electrodes, controls the observed TER effect. Our results will help unravel the TER mechanism of asymmetric FTJs in most experiments and will be useful for the designing of FTJ-based devices.

Authors:
;  [1]
  1. Department of Physics and the Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong (China)
Publication Date:
OSTI Identifier:
22596784
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 22; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ASYMMETRY; CONTROL; ELECTRODES; FERROELECTRIC MATERIALS; FILMS; LEAD COMPOUNDS; LENGTH; METALS; POLARIZATION; SCREENING; TITANATES; TRANSPORT THEORY; TUNNEL EFFECT; TUNNEL JUNCTIONS; WORK FUNCTIONS

Citation Formats

Tao, L. L., and Wang, J., E-mail: jianwang@hku.hk. Ferroelectricity and tunneling electroresistance effect in asymmetric ferroelectric tunnel junctions. United States: N. p., 2016. Web. doi:10.1063/1.4953642.
Tao, L. L., & Wang, J., E-mail: jianwang@hku.hk. Ferroelectricity and tunneling electroresistance effect in asymmetric ferroelectric tunnel junctions. United States. doi:10.1063/1.4953642.
Tao, L. L., and Wang, J., E-mail: jianwang@hku.hk. 2016. "Ferroelectricity and tunneling electroresistance effect in asymmetric ferroelectric tunnel junctions". United States. doi:10.1063/1.4953642.
@article{osti_22596784,
title = {Ferroelectricity and tunneling electroresistance effect in asymmetric ferroelectric tunnel junctions},
author = {Tao, L. L. and Wang, J., E-mail: jianwang@hku.hk},
abstractNote = {We report the investigation on the ferroelectricity and tunneling electroresistance (TER) effect in PbTiO{sub 3} (PTO)-based ferroelectric tunnel junctions (FTJs) using first-principles calculations. For symmetric FTJs, we have calculated the average polarizations of PTO film and effective screening lengths of different metal electrodes for a number of FTJs, which is useful for experimental research. For asymmetric FTJs, significant asymmetric ferroelectric displacements in PTO film are observed, which is attributed to the intrinsic field generated by the two dissimilar electrodes. Moreover, by performing quantum transport calculations on those asymmetric FTJs, a sizable TER effect is observed. It is found that the asymmetry of ferroelectric displacements in PTO barrier, which is determined by the difference of work functions of the electrodes, controls the observed TER effect. Our results will help unravel the TER mechanism of asymmetric FTJs in most experiments and will be useful for the designing of FTJ-based devices.},
doi = {10.1063/1.4953642},
journal = {Journal of Applied Physics},
number = 22,
volume = 119,
place = {United States},
year = 2016,
month = 6
}
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