Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurization

Sulfur is a promising anion dopant for exploring exotic physical phenomena in complex perovskite oxides. However, sulfurization to the epitaxial single-crystal oxide thin films with high crystallinity is experimentally challenging due to the volatility of sulfur element; thus, sulfurization effects...

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Main Authors: Xuan Luc Le, Nguyen Dang Phu, Nguyen Xuan Duong
Format: Article
Language:English
Published: AIMS Press 2024-09-01
Series:AIMS Materials Science
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Online Access:https://www.aimspress.com/article/doi/10.3934/matersci.2024039?viewType=HTML
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author Xuan Luc Le
Nguyen Dang Phu
Nguyen Xuan Duong
author_facet Xuan Luc Le
Nguyen Dang Phu
Nguyen Xuan Duong
author_sort Xuan Luc Le
collection DOAJ
description Sulfur is a promising anion dopant for exploring exotic physical phenomena in complex perovskite oxides. However, sulfurization to the epitaxial single-crystal oxide thin films with high crystallinity is experimentally challenging due to the volatility of sulfur element; thus, sulfurization effects on the associated properties have been scarcely studied. Here, we demonstrate an enhancement of ferroelectric polarization of epitaxial BaTiO<sub>3</sub> thin films by sulfur doping. Initially, the epitaxial BaTiO<sub>3</sub> thin films with high crystallinity were grown by pulsed laser deposition (PLD). Then, sulfurization to epitaxial BaTiO<sub>3</sub> films was performed using a precursor of thiourea (CH<sub>4</sub>N<sub>2</sub>S) solution via a spin-coating technique. The crystalline structure of sulfurized BaTiO<sub>3</sub> films was identified by X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). The structural distortion with the elongated out-of-plane lattice constant was observed in the sulfurized BaTiO<sub>3</sub> films. Atomic force microscopy (AFM) analyses also confirmed the surface morphology of films after sulfurization. Interestingly, we found an enhanced ferroelectric polarization in sulfur-doped BaTiO<sub>3</sub> films accompanying the improved tetragonality in the crystal structure after sulfurization. The increments in the remnant (~34.8%) and saturated (~30.6%) polarizations of sulfurized BaTiO<sub>3</sub> films were obtained in comparison with pure BaTiO<sub>3</sub> films. Our work could be a primary study for a thorough understanding of the sulfur doping effect in perovskite oxides, opening up the potential of oxysulfide materials.
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spelling doaj-art-e4f39791fa4f4f4996e58a4384f7f08e2025-08-20T01:47:38ZengAIMS PressAIMS Materials Science2372-04842024-09-0111480281410.3934/matersci.2024039Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurizationXuan Luc Le0Nguyen Dang Phu1Nguyen Xuan Duong2Faculty of Electronics and Telecommunications, VNU University of Engineering and Technology, E3 Building, 144 Xuan Thuy, Hanoi 100000, VietnamFaculty of Electronics and Telecommunications, VNU University of Engineering and Technology, E3 Building, 144 Xuan Thuy, Hanoi 100000, VietnamFaculty of Electronics and Telecommunications, VNU University of Engineering and Technology, E3 Building, 144 Xuan Thuy, Hanoi 100000, VietnamSulfur is a promising anion dopant for exploring exotic physical phenomena in complex perovskite oxides. However, sulfurization to the epitaxial single-crystal oxide thin films with high crystallinity is experimentally challenging due to the volatility of sulfur element; thus, sulfurization effects on the associated properties have been scarcely studied. Here, we demonstrate an enhancement of ferroelectric polarization of epitaxial BaTiO<sub>3</sub> thin films by sulfur doping. Initially, the epitaxial BaTiO<sub>3</sub> thin films with high crystallinity were grown by pulsed laser deposition (PLD). Then, sulfurization to epitaxial BaTiO<sub>3</sub> films was performed using a precursor of thiourea (CH<sub>4</sub>N<sub>2</sub>S) solution via a spin-coating technique. The crystalline structure of sulfurized BaTiO<sub>3</sub> films was identified by X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). The structural distortion with the elongated out-of-plane lattice constant was observed in the sulfurized BaTiO<sub>3</sub> films. Atomic force microscopy (AFM) analyses also confirmed the surface morphology of films after sulfurization. Interestingly, we found an enhanced ferroelectric polarization in sulfur-doped BaTiO<sub>3</sub> films accompanying the improved tetragonality in the crystal structure after sulfurization. The increments in the remnant (~34.8%) and saturated (~30.6%) polarizations of sulfurized BaTiO<sub>3</sub> films were obtained in comparison with pure BaTiO<sub>3</sub> films. Our work could be a primary study for a thorough understanding of the sulfur doping effect in perovskite oxides, opening up the potential of oxysulfide materials.https://www.aimspress.com/article/doi/10.3934/matersci.2024039?viewType=HTMLsulfurizationperovskite oxidesferroelectricityepitaxythin film
spellingShingle Xuan Luc Le
Nguyen Dang Phu
Nguyen Xuan Duong
Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurization
AIMS Materials Science
sulfurization
perovskite oxides
ferroelectricity
epitaxy
thin film
title Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurization
title_full Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurization
title_fullStr Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurization
title_full_unstemmed Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurization
title_short Enhancement of ferroelectricity in perovskite BaTiO<sub>3</sub> epitaxial thin films by sulfurization
title_sort enhancement of ferroelectricity in perovskite batio sub 3 sub epitaxial thin films by sulfurization
topic sulfurization
perovskite oxides
ferroelectricity
epitaxy
thin film
url https://www.aimspress.com/article/doi/10.3934/matersci.2024039?viewType=HTML
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AT nguyendangphu enhancementofferroelectricityinperovskitebatiosub3subepitaxialthinfilmsbysulfurization
AT nguyenxuanduong enhancementofferroelectricityinperovskitebatiosub3subepitaxialthinfilmsbysulfurization