A single layer of LaAlO3 with a nominal thickness of one unit cell, which is sandwiched between a SrTiO3 substrate and a SrTiO3 capping layer, is quantitatively investigated by high-resolution transmission electron microscopy. By the use of an aberration-corrected electron microscope and by employing sophisticated numerical image simulation procedures, significant progress is made in two aspects. First, the structural as well as the chemical features of the interface are determined simultaneously on an atomic scale from the same specimen area. Second, the evaluation of the structural and chemical data is carried out in a fully quantitative way on the basis of the absolute image contrast, which has not been achieved so far in materials science investigations using high-resolution electron microscopy. Considering the strong influence of even subtle structural details on the electronic properties of interfaces in oxide materials, a fully quantitative interface analysis, which makes positional data available with picometer precision together with the related chemical information, can contribute to a better understanding of the functionality of such interfaces.
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http://dx.doi.org/10.1017/S1431927612014407 | DOI Listing |
ACS Nano
December 2024
Department of Energy Systems Research, Ajou University, Suwon 16499, Republic of Korea.
Photodetectors that detect near-infrared (NIR) light serve as important components in contemporary energy-efficient optoelectronic devices. However, detecting the low-energy photons of the NIR light has long been challenging since the ease of photoexcitation inevitably involves increasing the background current in the dark. Herein, we report the atomic-scale interface modification in SrRuO/LaAlO/Nb-doped SrTiO (SRO/LAO/Nb:STO) heterostructures for NIR photodetection.
View Article and Find Full Text PDFSmall Methods
October 2024
School of Materials Engineering, Purdue University, West Lafayette, Indiana, 47907, United States.
Nano Lett
October 2024
CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China.
Modern quantum device fabrication often requires precisely adding and removing materials at nanoscales, which is challenging for high-quality correlated oxide devices. In this work, we present a novel nanofabrication method that remotely controls the interfacial metal-insulator transition at the LaAlO/SrTiO interface by selectively removing an LaAlO overlayer using a diamond tip. Remarkably, we observe a large force window within which single atomic layer precision of control is achievable.
View Article and Find Full Text PDFNat Commun
June 2024
Department of Energy Engineering, KENTECH Institute for Energy Materials and Devices, Korea Institute of Energy Technology (KENTECH), Naju, Republic of Korea.
Since the discovery of two-dimensional electron gas at the LaAlO/SrTiO interface, its intriguing physical properties have garnered significant interests for device applications. Yet, understanding its response to electrical stimuli remains incomplete. Our in-situ transmission electron microscopy analysis of a LaAlO/SrTiO two-dimensional electron gas device under electrical bias reveals key insights.
View Article and Find Full Text PDFACS Appl Mater Interfaces
February 2024
School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, China.
The recent discovery of superconductivity in infinite-layer Sr-doped NdNiO grown on SrTiO(001) provides a new platform to explore the conducting mechanism of unconventional superconductors. However, the electronic structure of infinite-layer nickelates remains controversial. In this paper, we systematically compare the structural and electronic properties of NdNiO films grown on SrTiO and LaAlO substrates using first-principles calculations.
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