Influence of Chemistry and Misfit Dislocation Structure on Dopant Segregation at Complex Oxide Heterointerfaces
Abstract
Abstract Complex oxide heterostructures and thin films have emerged as promising candidates for diverse applications. Lattice mismatch between the two oxides lead to the formation of misfit dislocations, which influence vital material features. Trivalent dopant segregation to misfit dislocations at semi‐coherent oxide heterointerfaces, while not well understood, is anticipated to impact interface‐governed properties. Here, atomistic simulations elucidating the influence of misfit dislocations on dopant segregation at SrTiO 3 /MgO heterointerfaces are reported. SrO‐ and TiO 2 ‐terminated interfaces that have differing misfit dislocation structure were considered for trivalent dopants segregation. At SrO‐terminated interface, dopants tend to segregate toward but not precisely to the heterointerface, whereas at TiO 2 ‐terminated interface, dopants exhibit a thermodynamic preference to accumulate at the heterointerface. Most favorable segregation sites at SrO‐terminated interface are located within the coherent terrace, whereas those at TiO 2 ‐terminated interface are at misfit dislocation intersections. Atomic layer chemistry and the resulting misfit dislocation structure at the heterointerface, along with concomitant strain at the heterointerface due to mismatched dopants, play a critical role in influencing the observed trends for dopant segregation. Overall, the present results offer a fundamental atomic scale perspective of dopant behavior at semi‐coherent complex oxide heterointerfaces and themore »
- Authors:
-
[1];
- Rochester Inst. of Technology, NY (United States). School of Physics and Astronomy
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Publication Date:
- Research Org.:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Rochester Inst. of Technology, NY (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA); LANL Laboratory Directed Research and Development (LDRD) Program; Rochester Inst. of Technology (United States)
- OSTI Identifier:
- 1483545
- Alternate Identifier(s):
- OSTI ID: 1472209
- Report Number(s):
- LA-UR-18-28638
Journal ID: ISSN 2513-0390
- Grant/Contract Number:
- 89233218CNA000001
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Advanced Theory and Simulations
- Additional Journal Information:
- Journal Volume: 2; Journal Issue: 1; Journal ID: ISSN 2513-0390
- Publisher:
- Wiley
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; atomistic simulations; complex oxide heterostructures; dopant segregation; misfit dislocations; strain at heterointerfaces
Citation Formats
Dholabhai, Pratik P., Martinez, Enrique, and Uberuaga, Blas P. Influence of Chemistry and Misfit Dislocation Structure on Dopant Segregation at Complex Oxide Heterointerfaces. United States: N. p., 2018.
Web. doi:10.1002/adts.201800095.
Dholabhai, Pratik P., Martinez, Enrique, & Uberuaga, Blas P. Influence of Chemistry and Misfit Dislocation Structure on Dopant Segregation at Complex Oxide Heterointerfaces. United States. https://doi.org/10.1002/adts.201800095
Dholabhai, Pratik P., Martinez, Enrique, and Uberuaga, Blas P. Mon .
"Influence of Chemistry and Misfit Dislocation Structure on Dopant Segregation at Complex Oxide Heterointerfaces". United States. https://doi.org/10.1002/adts.201800095. https://www.osti.gov/servlets/purl/1483545.
@article{osti_1483545,
title = {Influence of Chemistry and Misfit Dislocation Structure on Dopant Segregation at Complex Oxide Heterointerfaces},
author = {Dholabhai, Pratik P. and Martinez, Enrique and Uberuaga, Blas P.},
abstractNote = {Abstract Complex oxide heterostructures and thin films have emerged as promising candidates for diverse applications. Lattice mismatch between the two oxides lead to the formation of misfit dislocations, which influence vital material features. Trivalent dopant segregation to misfit dislocations at semi‐coherent oxide heterointerfaces, while not well understood, is anticipated to impact interface‐governed properties. Here, atomistic simulations elucidating the influence of misfit dislocations on dopant segregation at SrTiO 3 /MgO heterointerfaces are reported. SrO‐ and TiO 2 ‐terminated interfaces that have differing misfit dislocation structure were considered for trivalent dopants segregation. At SrO‐terminated interface, dopants tend to segregate toward but not precisely to the heterointerface, whereas at TiO 2 ‐terminated interface, dopants exhibit a thermodynamic preference to accumulate at the heterointerface. Most favorable segregation sites at SrO‐terminated interface are located within the coherent terrace, whereas those at TiO 2 ‐terminated interface are at misfit dislocation intersections. Atomic layer chemistry and the resulting misfit dislocation structure at the heterointerface, along with concomitant strain at the heterointerface due to mismatched dopants, play a critical role in influencing the observed trends for dopant segregation. Overall, the present results offer a fundamental atomic scale perspective of dopant behavior at semi‐coherent complex oxide heterointerfaces and the interplay between dopant chemistry, interface chemistry, and misfit dislocation structure.},
doi = {10.1002/adts.201800095},
journal = {Advanced Theory and Simulations},
number = 1,
volume = 2,
place = {United States},
year = {Mon Sep 24 00:00:00 EDT 2018},
month = {Mon Sep 24 00:00:00 EDT 2018}
}
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Figure 1: Structure of misfit dislocations at (a) SrO-terminated interface; (b) TiO2terminated interface. For both the cases, only interface layers are shown. View is normal to the interface. Green, blue, and yellow spheres correspond to Sr, Ti, and Mg atoms respectively. Oxygen atoms in STO are indicated by red spheres,more »
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Works referenced in this record:
All-solid-state electric-double-layer transistor based on oxide ion migration in Gd-doped CeO 2 on SrTiO 3 single crystal
journal, August 2013
- Tsuchiya, Takashi; Terabe, Kazuya; Aono, Masakazu
- Applied Physics Letters, Vol. 103, Issue 7
Temperature Dependence Discontinuity in the Stability of Manganese-Doped Ceria Nanocrystals
journal, January 2017
- Wu, Longjia; Dholabhai, Pratik P.; Uberuaga, Blas P.
- Crystal Growth & Design, Vol. 17, Issue 2
Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films
journal, October 2015
- Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie
- Nature Communications, Vol. 6, Issue 1
Misfit Dislocation Guided Topographic and Conduction Patterning in Complex Oxide Epitaxial Thin Films
journal, April 2016
- Sandiumenge, Felip; Bagués, Núria; Santiso, José
- Advanced Materials Interfaces, Vol. 3, Issue 14
Shape Transitions of Epitaxial Islands during Strained Layer Growth: Anatase on
journal, April 2009
- Marshall, Matthew S. J.; Castell, Martin R.
- Physical Review Letters, Vol. 102, Issue 14
Catalysis by Doped Oxides
journal, December 2012
- McFarland, Eric W.; Metiu, Horia
- Chemical Reviews, Vol. 113, Issue 6
Defect association in acceptor-doped SrTiO 3 : case study for Fe′TiV˙˙O and Mn″TiV˙˙O
journal, January 2003
- Merkle, Rotraut; Maier, Joachim
- Phys. Chem. Chem. Phys., Vol. 5, Issue 11
Physics of SrTiO 3 -based heterostructures and nanostructures: a review
journal, February 2018
- Pai, Yun-Yi; Tylan-Tyler, Anthony; Irvin, Patrick
- Reports on Progress in Physics, Vol. 81, Issue 3
Probing dopant segregation in distinct cation sites at perovskite oxide polycrystal interfaces
journal, November 2017
- Yoon, Hye-In; Lee, Dong-Kyu; Bae, Hyung Bin
- Nature Communications, Vol. 8, Issue 1
Influence of acceptor doping on ionic conductivity in alkali earth titanate perovskites
journal, May 2002
- Dunyushkina, L. A.; Mashkina, E. A.; Nechaev, I. Yu.
- Ionics, Vol. 8, Issue 3-4
Segregation of Mn 2+ Dopants as Interstitials in SrTiO 3 Grain Boundaries
journal, October 2013
- Yang, Hao; Kotula, Paul G.; Sato, Yukio
- Materials Research Letters, Vol. 2, Issue 1
Radiation Tolerant Interfaces: Influence of Local Stoichiometry at the Misfit Dislocation on Radiation Damage Resistance of Metal/Oxide Interfaces
journal, April 2017
- Shutthanandan, Vaithiyalingam; Choudhury, Samrat; Manandhar, Sandeep
- Advanced Materials Interfaces, Vol. 4, Issue 14
Cu2O/TiO2 heterostructure nanotube arrays prepared by an electrodeposition method exhibiting enhanced photocatalytic activity for CO2 reduction to methanol
journal, February 2014
- Wang, Junyi; Ji, Guangbin; Liu, Yousong
- Catalysis Communications, Vol. 46
Influence of interfacial dislocations on hysteresis loops of ferroelectric films
journal, November 2008
- Li, Y. L.; Hu, S. Y.; Choudhury, S.
- Journal of Applied Physics, Vol. 104, Issue 10
Fast Parallel Algorithms for Short-Range Molecular Dynamics
journal, March 1995
- Plimpton, Steve
- Journal of Computational Physics, Vol. 117, Issue 1
Atomic and electronic surface structures of dopants in oxides: STM and XPS of Nb- and La-doped SrTiO (001)
journal, January 2011
- Marshall, Matthew S. J.; Newell, David T.; Payne, David J.
- Physical Review B, Vol. 83, Issue 3
The effects of lattice strain, dislocations, and microstructure on the transport properties of YSZ films
journal, January 2017
- Harrington, George F.; Cavallaro, Andrea; McComb, David W.
- Physical Chemistry Chemical Physics, Vol. 19, Issue 22
Solution Mechanisms for Dopant Oxides in Yttria
journal, June 1999
- Busker, Gerdjan; Chroneos, Alex; Grimes, Robin W.
- Journal of the American Ceramic Society, Vol. 82, Issue 6
Colossal Ionic Conductivity at Interfaces of Epitaxial ZrO2:Y2O3/SrTiO3 Heterostructures
journal, August 2008
- Garcia-Barriocanal, J.; Rivera-Calzada, A.; Varela, M.
- Science, Vol. 321, Issue 5889
Magnetization in electron- and Mn- doped SrTiO3
journal, March 2013
- Choudhury, D.; Pal, B.; Sharma, A.
- Scientific Reports, Vol. 3, Issue 1
Effect of Sintering Atmosphere on Grain Boundary Segregation and Grain Growth in Niobium-Doped SrTiO3
journal, November 2002
- Chung, Sung-Yoon; Kang, Suk-Joong L.; Dravid, Vinayak P.
- Journal of the American Ceramic Society, Vol. 85, Issue 11
Theory of the Dielectric Constants of Alkali Halide Crystals
journal, October 1958
- Dick, B. G.; Overhauser, A. W.
- Physical Review, Vol. 112, Issue 1
Structure and Dielectric Properties of Re 0.02 Sr 0.97 TiO 3 ( Re = La,Sm,Gd,Er) Ceramics for High-Voltage Capacitor Applications
journal, April 2013
- Shen, Zong-Yang; Hu, Qi-Guo; Li, Yue-Ming
- Journal of the American Ceramic Society, Vol. 96, Issue 8
Structural and electronic properties of -doped and -doped
journal, December 2004
- Luo, Weidong; Duan, Wenhui; Louie, Steven G.
- Physical Review B, Vol. 70, Issue 21
Dopant Segregation and Space Charge Effects in Proton-Conducting BaZrO 3 Perovskites
journal, November 2011
- Shirpour, Mona; Rahmati, Behnaz; Sigle, Wilfried
- The Journal of Physical Chemistry C, Vol. 116, Issue 3
Control of epitaxial relationships of ZnO/SrTiO3 heterointerfaces by etching the substrate surface
journal, January 2013
- Jia, Caihong; Chen, Yonghai; Liu, Xianglin
- Nanoscale Research Letters, Vol. 8, Issue 1
Lattice relaxation and charge-transfer optical transitions due to self-trapped holes in nonstoichiometric LaMnO3 crystal
journal, January 2002
- Kovaleva, N. N.; Gavartin, J. L.; Shluger, A. L.
- Journal of Experimental and Theoretical Physics, Vol. 94, Issue 1
Scale Up and Anode Development for La-Doped SrTiO 3 Anode-Supported SOFCs
journal, April 2013
- Savaniu, Cristian-Daniel; Miller, David N.; Irvine, John T. S.
- Journal of the American Ceramic Society, Vol. 96, Issue 6
Massive Interfacial Reconstruction at Misfit Dislocations in Metal/Oxide Interfaces
journal, October 2014
- Choudhury, Samrat; Morgan, Dane; Uberuaga, Blas Pedro
- Scientific Reports, Vol. 4, Issue 1
Stabilization of MgAl2O4 spinel surfaces via doping
journal, July 2016
- Hasan, Md. M.; Dholabhai, Pratik P.; Castro, Ricardo H. R.
- Surface Science, Vol. 649
Low-Temperature Ionic Conductivity of an Acceptor-Doped Perovskite: I. Impedance of Single-Crystal SrTiO 3
journal, June 2016
- Maier, Russell A.; Randall, Clive A.
- Journal of the American Ceramic Society, Vol. 99, Issue 10
The classical equation of state of gaseous helium, neon and argon
journal, October 1938
- Buckingham, R. A.
- Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, Vol. 168, Issue 933, p. 264-283
Electronic and Chemical Properties of a Surface-Terminated Screw Dislocation in MgO
journal, December 2013
- McKenna, Keith P.
- Journal of the American Chemical Society, Vol. 135, Issue 50
Defect Distributions and Transport in Nanocomposites: A Theoretical Perspective
journal, July 2013
- Pedro Uberuaga, Blas; Martinez, Enrique; Bi, Zhenxing
- Materials Research Letters, Vol. 1, Issue 4
Electrical conductivity and segregation effects of doped SrTiO3 thin films
journal, January 2001
- Ohly, Christian; Hoffmann-Eifert, Susanne; Szot, Krzysztof
- Journal of the European Ceramic Society, Vol. 21, Issue 10-11
Local Structure and Energetics of Pr- and La-Doped SrTiO 3 Grain Boundaries and the Influence on Core–Shell Structure Formation
journal, October 2014
- Dawson, James A.; Tanaka, Isao
- The Journal of Physical Chemistry C, Vol. 118, Issue 44
Breakthrough fuel cell technology using ceria-based multi-functional nanocomposites
journal, June 2013
- Zhu, Bin; Fan, Liangdong; Lund, Peter
- Applied Energy, Vol. 106
Linking Interfacial Step Structure and Chemistry with Locally Enhanced Radiation-Induced Amorphization at Oxide Heterointerfaces
journal, April 2014
- Aguiar, Jeffery A.; Dholabhai, Pratik P.; Bi, Zhenxing
- Advanced Materials Interfaces, Vol. 1, Issue 4
Structure and segregation of dopant–defect complexes at grain boundaries in nanocrystalline doped ceria
journal, January 2015
- Dholabhai, Pratik P.; Aguiar, Jeffery A.; Wu, Longjia
- Physical Chemistry Chemical Physics, Vol. 17, Issue 23
Evidence of the pressure-induced conductivity switching of yttrium-doped SrTiO 3
journal, September 2016
- Dai, LiDong; Wu, Lei; Li, HePing
- Journal of Physics: Condensed Matter, Vol. 28, Issue 47
Orientation-specific amorphization and intercalated recrystallization at ion-irradiated SrTiO 3 /MgO interfaces
journal, August 2014
- Aguiar, Jeffery A.; Zhuo, Mujin; Bi, Zhenxing
- Journal of Materials Research, Vol. 29, Issue 16
Cationic Surface Segregation in Donor-Doped SrTiO3 Under Oxidizing Conditions
journal, November 2002
- Meyer, René; Waser, Rainer; Helmbold, Julia
- Journal of Electroceramics, Vol. 9, Issue 2, p. 101-110
Optical spectroscopy of erbium-doped SrTiO3 crystals
journal, October 2014
- Potůček, Z.; Skvortsov, A. P.; Poletaev, N. K.
- Journal of Luminescence, Vol. 154
Dielectric measurements, Raman scattering and surface studies of Sm-doped SrTiO3 single crystal
journal, April 2010
- Maletic, S.; Popovic, D.; Dojcilovic, J.
- Journal of Alloys and Compounds, Vol. 496, Issue 1-2
Amphoteric doping of praseodymium Pr3+ in SrTiO3 grain boundaries
journal, March 2015
- Yang, H.; Lee, H. S.; Kotula, P. G.
- Applied Physics Letters, Vol. 106, Issue 12
On the photoluminescence behavior of samarium-doped strontium titanate nanostructures under UV light. A structural and electronic understanding
journal, January 2010
- Longo, Valéria Moraes; das Graça Sampaio Costa, Maria; Zirpole Simões, Alexandre
- Physical Chemistry Chemical Physics, Vol. 12, Issue 27
δ-Doping Effects on Electronic and Energetic Properties of LaAlO 3 /SrTiO 3 Heterostructure: First-Principles Analysis of 23 Transition-Metal Dopants
journal, August 2017
- Cheng, Jianli; Wang, Yaqin; Luo, Jian
- Advanced Materials Interfaces, Vol. 4, Issue 21
Role of the interface on radiation damage in the SrTiO 3 /LaAlO 3 heterostructure under Ne 2+ ion irradiation
journal, March 2014
- Bi, Zhenxing; Uberuaga, Blas P.; Vernon, L. J.
- Journal of Applied Physics, Vol. 115, Issue 12
Self-Arranged Misfit Dislocation Network Formation upon Strain Release in La 0.7 Sr 0.3 MnO 3 /LaAlO 3 (100) Epitaxial Films under Compressive Strain
journal, June 2016
- Santiso, José; Roqueta, Jaume; Bagués, Núria
- ACS Applied Materials & Interfaces, Vol. 8, Issue 26
Origin of Interface Magnetism in and Heterostructures
journal, August 2013
- Salluzzo, M.; Gariglio, S.; Stornaiuolo, D.
- Physical Review Letters, Vol. 111, Issue 8
Low-Temperature Superionic Conductivity in Strained Yttria-Stabilized Zirconia
journal, May 2010
- Sillassen, Michael; Eklund, Per; Pryds, Nini
- Advanced Functional Materials, Vol. 20, Issue 13
Defect cluster formation in M2O3-doped cubic ZrO2
journal, February 2000
- Zacate, M.
- Solid State Ionics, Vol. 128, Issue 1-4
Ionic conductivity in oxide heterostructures: the role of interfaces
journal, October 2010
- Fabbri, Emiliana; Pergolesi, Daniele; Traversa, Enrico
- Science and Technology of Advanced Materials, Vol. 11, Issue 5
Optimization of Flux Pinning in Bulk Melt Textured 1-2-3 Superconductors: Bringing Dislocations under Control
journal, March 2000
- Sandiumenge, F.; Puig, T.; Rabier, J.
- Advanced Materials, Vol. 12, Issue 5
Termination chemistry-driven dislocation structure at SrTiO3/MgO heterointerfaces
journal, September 2014
- Dholabhai, Pratik P.; Pilania, Ghanshyam; Aguiar, Jeffery A.
- Nature Communications, Vol. 5, Issue 1
Ionic conductivity and activation energy for oxygen ion transport in superlattices—the semicoherent multilayer system YSZ (ZrO2 + 9.5 mol% Y2O3)/Y2O3
journal, January 2008
- Korte, C.; Peters, A.; Janek, J.
- Physical Chemistry Chemical Physics, Vol. 10, Issue 31
Radiation-induced amorphization resistance and radiation tolerance in structurally related oxides
journal, February 2007
- Sickafus, Kurt E.; Grimes, Robin W.; Valdez, James A.
- Nature Materials, Vol. 6, Issue 3
Emergent phenomena at oxide interfaces
journal, January 2012
- Hwang, H. Y.; Iwasa, Y.; Kawasaki, M.
- Nature Materials, Vol. 11, Issue 2
Interatomic potentials for strontium titanate: An assessment of their transferability and comparison with density functional theory
journal, August 2008
- Benedek, Nicole A.; Chua, Alvin L. -S.; Elsässer, Christian
- Physical Review B, Vol. 78, Issue 6
High-frequency electron paramagnetic resonance investigation of Mn3+ centers in SrTiO3
journal, July 2012
- Azamat, D. V.; Badalyan, A. G.; Dejneka, A.
- Journal of Physics and Chemistry of Solids, Vol. 73, Issue 7
Interface Energies of Nanocrystalline Doped Ceria: Effects of Manganese Segregation
journal, November 2015
- Wu, Longjia; Aguiar, Jeffery A.; Dholabhai, Pratik P.
- The Journal of Physical Chemistry C, Vol. 119, Issue 49
Segregation of xenon to dislocations and grain boundaries in uranium dioxide
journal, November 2011
- Nerikar, P. V.; Parfitt, D. C.; Casillas Trujillo, L. A.
- Physical Review B, Vol. 84, Issue 17
On the mobility of carriers at semi-coherent oxide heterointerfaces
journal, January 2017
- Dholabhai, Pratik P.; Martínez, Enrique; Brown, Nicholas T.
- Physical Chemistry Chemical Physics, Vol. 19, Issue 34
Cation Size Mismatch and Charge Interactions Drive Dopant Segregation at the Surfaces of Manganite Perovskites
journal, May 2013
- Lee, Wonyoung; Han, Jeong Woo; Chen, Yan
- Journal of the American Chemical Society, Vol. 135, Issue 21
Dopant size effects on novel functionalities: High-temperature interfacial superconductivity
journal, March 2017
- Suyolcu, Y. Eren; Wang, Yi; Baiutti, Federico
- Scientific Reports, Vol. 7, Issue 1
Defect interactions with stepped CeO 2 /SrTiO 3 interfaces: Implications for radiation damage evolution and fast ion conduction
journal, May 2014
- Dholabhai, Pratik P.; Aguiar, Jeffery A.; Misra, Amit
- The Journal of Chemical Physics, Vol. 140, Issue 19
Die Berechnung optischer und elektrostatischer Gitterpotentiale
journal, January 1921
- Ewald, P. P.
- Annalen der Physik, Vol. 369, Issue 3
Monitoring the Structural and Vibrational Properties in RE-Doped SrTiO 3 Ceramic Powders
journal, July 2016
- Abreu, Yuslín G.; Soares, Julia C.; Moreira, Roberto L.
- The Journal of Physical Chemistry C, Vol. 120, Issue 30
Electrical Properties of Yttrium-Doped Strontium Titanate under Reducing Conditions
journal, January 2002
- Hui, Shiqiang; Petric, Anthony
- Journal of The Electrochemical Society, Vol. 149, Issue 1, p. J1-J10
Materials for Intermediate-Temperature Solid-Oxide Fuel Cells
journal, July 2014
- Kilner, John A.; Burriel, Mónica
- Annual Review of Materials Research, Vol. 44, Issue 1
Magnetization in electron- and Mn- doped SrTiO3
text, January 2013
- Choudhury, D.; Pal, B.; Sharma, A.
- arXiv
Physics of SrTiO$_3$-based heterostructures and nanostructures: a review
text, January 2017
- Pai, Yun-Yi; Tylan-Tyler, Anthony; Irvin, Patrick
- arXiv
Works referencing / citing this record:
Beyond Coherent Oxide Heterostructures: Atomic‐Scale Structure of Misfit Dislocations
journal, June 2019
- Dholabhai, Pratik P.; Uberuaga, Blas P.
- Advanced Theory and Simulations, Vol. 2, Issue 9
Atomic-scale structure of misfit dislocations in CeO 2 /MgO heterostructures and thermodynamic stability of dopant–defect complexes at the heterointerface
journal, January 2019
- Dholabhai, Pratik P.
- Physical Chemistry Chemical Physics, Vol. 21, Issue 37
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journal, October 2019
- Uberuaga, Blas Pedro; Dholabhai, Pratik P.; Pilania, Ghanshyam
- APL Materials, Vol. 7, Issue 10
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