Publications de Duncan Thomas Lindsay Alexander

A Multiscale Bayesian Approach to Quantification and Denoising of Energy-dispersive X-ray Data

Cécile Hébert, Duncan Thomas Lindsay Alexander

Energy dispersive x-ray (EDX) spectrum imaging yields compositional information with a spatial resolution down to the atomic level. However, experimental limitations often produce extremely sparse and noisy EDX spectra. Under such conditions, every detecte ...

IOP Publishing Ltd2025

Engineering Symmetry Breaking Interfaces by Nanoscale Structural-Energetics in Orthorhombic Perovskite Thin Films

Duncan Thomas Lindsay Alexander, Bernat Mundet

The atomic configuration of phases and their interfaces is fundamental to materials design and engineering. Here, we unveil a transition metal oxide interface, whose formation is driven by energetic influences─epitaxial tensile strain versus oxygen octahed ...

2025

Investigating domain structures and superdomains in ferroelectric PbTiO3 based heterostructures on DyScO3

Duncan Thomas Lindsay Alexander

This work focuses on the complex ferroelastic/ferroelectric domain structure in the prototypical ferroelectric PbTiO3 epitaxially strained on (110)o-oriented DyScO3 substrates, with a 22 nm-thick bottom SrRuO3 electrode. High quality epitaxial growth has b ...

2025

Synaptic and neuronal functionalities on a single oxide film via interface engineering

Duncan Thomas Lindsay Alexander

Achieving both volatile and nonvolatile resistive switching in the same material platform is a key milestone towards the development of dense hardware-based neuromorphic computing. We show that, by suitable choice of electrode metals, a single oxide film c ...

American Physical Society (APS)2025

Structural study of nickelate based heterostructures

Duncan Thomas Lindsay Alexander, Chih-Ying Hsu, Bernat Mundet, Jean-Marc Triscone

Heterostructures consisting of SmNiO3 and NdNiO3 alternating layers with additional LaAlO3 spacer layers were grown and fully characterized by means of x-ray diffraction, atomic force microscopy, and scanning transmission electron microscopy. A change in t ...

Aip Publishing2024

Mapping orthorhombic domains with geometrical phase analysis in rare-earth nickelate heterostructures

Duncan Thomas Lindsay Alexander, Bernat Mundet, Jean-Marc Triscone

Most perovskite oxides belong to the Pbnm space group, composed of an anisotropic unit cell, A-site antipolar displacements, and oxygen octahedral tilts. Mapping the orientation of the orthorhombic unit cell in epitaxial heterostructures that consist of at ...

Aip Publishing2024

Leveraging Machine Learning for Advanced Nanoscale X-ray Analysis: Unmixing Multicomponent Signals and Enhancing Chemical Quantification

Cécile Hébert, Duncan Thomas Lindsay Alexander

Energy dispersive X-ray (EDX) spectroscopy in the transmission electron microscope is a key tool for nanomaterials analysis, providing a direct link between spatial and chemical information. However, using it for precisely determining chemical compositions ...

American Chemical Society (ACS)2024

Operando insights into correlating CO coverage and Cu-Au alloying with the selectivity of Au NP-decorated Cu2O nanocubes during the electrocatalytic CO2 reduction

Duncan Thomas Lindsay Alexander, Daniele Casari

Electrochemical reduction of CO2 (CO2RR) is an attractive technology to reintegrate the anthropogenic CO2 back into the carbon cycle driven by a suitable catalyst. This study employs highly efficient multi-carbon (C2+) producing Cu2O nanocubes (NCs) decora ...

ROYAL SOC CHEMISTRY2024

Electron-Beam Writing of Atomic-Scale Reconstructions at Oxide Interfaces

Duncan Thomas Lindsay Alexander, Chih-Ying Hsu

The epitaxial growth of complex oxides enables the production of high-quality films, yet substrate choice is restricted to certain symmetry and lattice parameters, thereby limiting the technological applications of epitaxial oxides. In comparison, the deve ...

American Chemical Society (ACS)2024

Role of the coupling of the electronic transitions on the order of the metal-to-insulator phase transition in nickelates

Duncan Thomas Lindsay Alexander

Rare-earth nickelates (chemical formula RNiO3, R being a rare-earth cation) display a temperature-dependent metal-to-insulator transition (MIT) together with a breathing distortion of the NiO6 octahedra units at a temperature ranging from 0 to 600 K depend ...

2024