Epitaxial growth of perovskite oxide films facilitated by oxygen vacancies

Tyunina, M.; Rusevich, Leonid L.; Kotomin, E. A.; Pacherová, O.; Kocourek, T.; Dejneka, A.

doi:10.1039/d0tc05750a

Cited by 26 publications

(27 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Epitaxial NNO films of ~ 20 nm in thickness were grown by pulsed laser deposition as described before 11 – 14 , 20 . To introduce oxygen vacancies, oxygen pressure of deposition, p O2 , was varied from 20 Pa for stoichiometric growth to as low as 0.1 Pa (see Methods section).…”

Section: Resultsmentioning

confidence: 99%

“…3 e). Interestingly, the energies for vacancy formation in different atomic planes may differ in magnitude by ~ 10% 8 , 10 , 15 , but the energies E DC and E DA can differ dramatically because of their signs 14 . Thus, the elastic properties, rather than the formation energy, can determine a type of the atomic planes, where vacancies are located in epitaxial films.…”

Section: Resultsmentioning

confidence: 99%

“…For instance, the out-of-plane dipoles can reduce elastic energy in compressively strained films and thus lead to an enlarged critical thickness for the relaxation of the misfit strain. Hence, relatively thick strained epitaxial films can be stabilized 14 . Moreover, a very large combined misfit-chemical strain can be achieved.…”

Section: Resultsmentioning

confidence: 99%

“…The nearest to vacancy Ti-cations shift away from the vacancy along the Ti–O-Ti–O-direction. The Ti-Vo-Ti distance elongates compared to the Ti–O-Ti distance 14 , 15 . This elongation is the primary mechanism, which determines the emergence of stress around the vacancy.…”

Section: Introductionmentioning

confidence: 96%

“…Here we focus on the poorly studied elastic properties of oxygen vacancies in AB O 3 perovskites. We have previously demonstrated that the elastic interactions of oxygen vacancies with substrate-imposed misfit strain can lead to a special spatial arrangement of the vacancies and thus stabilize epitaxial films of SrTiO 3 and BaTiO 3 11 – 14 . Both SrTiO 3 and BaTiO 3 are A 2+ B 4+ O 3 -type perovskites, where the formation of an oxygen vacancy (V O ) is associated with strong anisotropic lattice distortions.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Anisotropic chemical expansion due to oxygen vacancies in perovskite films

Tyunina

Pacherová

Kocourek

et al. 2021

Sci Rep

Self Cite

View full text Add to dashboard Cite

In scientifically intriguing and technologically important multifunctional ABO3 perovskite oxides, oxygen vacancies are most common defects. They cause lattice expansion and can alter the key functional properties. Here, it is demonstrated that contrary to weak isotropic expansion in bulk samples, oxygen vacancies produce strong anisotropic strain in epitaxial thin films. This anisotropic chemical strain is explained by preferential orientation of elastic dipoles of the vacancies. Elastic interaction of the dipoles with substrate-imposed misfit strain is suggested to define the dipolar orientation. Such elastic behavior of oxygen vacancies is anticipated to be general for perovskite films and have critical impacts on the film synthesis and response functions.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Anisotropic chemical expansion due to oxygen vacancies in perovskite films

Tyunina

Pacherová

Kocourek

et al. 2021

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

Thickness‐Dependent Thermal Conductivity and Phonon Mean Free Path Distribution in Single‐Crystalline Barium Titanate

et al. 2023

View full text Add to dashboard Cite

Nanosized perovskite ferroelectrics are widely employed in several electromechanical, photonics, and thermoelectric applications. Scaling of ferroelectric materials entails a severe reduction in the lattice (phonon) thermal conductivity, particularly at sub‐100 nm length scales. Such thermal conductivity reduction can be accurately predicted using the information of phonon mean free path (MFP) distribution. The current understanding of phonon MFP distribution in perovskite ferroelectrics is still inconclusive despite the critical thermal management implications. Here, high‐quality single‐crystalline barium titanate (BTO) thin films, a representative perovskite ferroelectric material, are grown at several thicknesses. Using experimental thermal conductivity measurements and first‐principles based modeling (including four‐phonon scattering), the phonon MFP distribution is determined in BTO. The simulation results agree with the measured thickness‐dependent thermal conductivity. The results show that the phonons with sub‐100 nm MFP dominate the thermal transport in BTO, and phonons with MFP exceeding 10 nm contribute ≈35% to the total thermal conductivity, in significant contrast to previously published experimental results. The experimentally validated phonon MFP distribution is consistent with the theoretical predictions of other complex crystals with strong anharmonicity. This work paves the way for thermal management in nanostructured and ferroelectric‐domain‐engineered systems for oxide perovskite‐based functional materials.

show abstract

Room Temperature Insulator‐to‐Metal Transition of VO₂/TiO₂ Epitaxial Bilayer Films Grown on M‐plane Sapphire Substrates

Chen

Kim

Cho

et al. 2021

Adv Elect Materials

View full text Add to dashboard Cite

Since the optoelectronic properties of VO2 are modulated around the critical temperature (Tc) of insulator‐to‐metal transition, VO2 is a promising candidate material for smart window. However, the Tc of bulk VO2 is rather high 341 K (68 °C) and therefore, needs to be decreased down to near temperature for practical applications. Although Tc can be reduced to room temperature if rutile TiO2 crystal is used as the substrate, it is not technologically viable for large‐scale applications because of the size limitation of available TiO2 crystal. Here, this work shows that the Tc can be reduced to near room temperature using M‐plane sapphire as the substrate. VO2/TiO2 bilayer films are fabricated with varied thicknesses on M‐plane sapphire [(100) α‐Al2O3] substrates. The 5.5‐nm‐thick VO2 film on 200‐nm‐thick TiO2 buffered sapphire substrate shows clear insulator‐to‐metal transition at ≈305 K (32 °C). It is also found that the insulator‐to‐metal transition is sensitive to the in‐plane lattice distortion, which induces carrier generation. The systematic study on the effect of in‐plane lattice distortion on the insulator‐to‐metal transition of VO2 will be useful for the practical application of VO2 as an active material of smart window.

show abstract

Epitaxial growth of perovskite oxide films facilitated by oxygen vacancies

Abstract: Anisotropic elastic dipoles of oxygen vacancies interact with substrate-induced misfit strain in epitaxial oxide films. This interaction leads to specific spatial alignment of the dipoles that facilitates coherent growth.

Cited by 26 publications

References 46 publications

Anisotropic chemical expansion due to oxygen vacancies in perovskite films

Anisotropic chemical expansion due to oxygen vacancies in perovskite films

Thickness‐Dependent Thermal Conductivity and Phonon Mean Free Path Distribution in Single‐Crystalline Barium Titanate

Room Temperature Insulator‐to‐Metal Transition of VO₂/TiO₂ Epitaxial Bilayer Films Grown on M‐plane Sapphire Substrates

Contact Info

Product

Resources

About

Epitaxial growth of perovskite oxide films facilitated by oxygen vacancies

Abstract: Anisotropic elastic dipoles of oxygen vacancies interact with substrate-induced misfit strain in epitaxial oxide films. This interaction leads to specific spatial alignment of the dipoles that facilitates coherent growth.

Cited by 26 publications

References 46 publications

Anisotropic chemical expansion due to oxygen vacancies in perovskite films

Anisotropic chemical expansion due to oxygen vacancies in perovskite films

Thickness‐Dependent Thermal Conductivity and Phonon Mean Free Path Distribution in Single‐Crystalline Barium Titanate

Room Temperature Insulator‐to‐Metal Transition of VO2/TiO2 Epitaxial Bilayer Films Grown on M‐plane Sapphire Substrates

Contact Info

Product

Resources

About

Room Temperature Insulator‐to‐Metal Transition of VO₂/TiO₂ Epitaxial Bilayer Films Grown on M‐plane Sapphire Substrates