Kalani Moore

• B.Sc. Applied Physics
• University of Limerick

Ferroelectric domain walls are a rich source of emergent electronic properties and unusual polar order. Recent studies showed that the configuration of ferroelectric walls can go well beyond the conventional Ising-type structure. N\'eel-, Bloch-, and vortex-like polar patterns have been observed, displaying strong similarities with the spin texture...

Recently, electrically conducting heterointerfaces between dissimilar band‐insulators (such as lanthanum aluminate and strontium titanate) have attracted considerable research interest. Charge transport has been thoroughly explored and fundamental aspects of conduction firmly established. Perhaps surprisingly, similar insights into conceptually muc...

Recently, electrically conducting heterointerfaces between dissimilar band-insulators (such as lanthanum aluminate and strontium titanate) have attracted considerable research interest. Charge transport has been thoroughly explored and fundamental aspects of conduction firmly established. Perhaps surprisingly, similar insights into conceptually muc...

The exotic internal structure of polar topologies in multiferroic materials offers a rich landscape for materials science research. As the spatial scale of these entities is often subatomic in nature, aberration-corrected transmission electron microscopy (TEM) is the ideal characterization technique. Software to quantify and visualize the slight sh...

Multiferroic topologies are an emerging solution for future low-power magnetic nanoelectronics due to their combined tuneable functionality and mobility. Here, we show that in addition to being magnetoelectric multiferroic at room temperature, thin-film Aurivillius phase Bi 6 Ti x Fe y Mn z O 18 is an ideal material platform for both domain wall an...

The exotic internal structure of polar topologies in multi-ferroic materials offers a rich landscape for materials science research. As the spatial scale of these entities are often sub-atomic in nature, aberration corrected transmission electron microscopy (TEM) is the ideal characterisation technique. Software to quantify and visualise the slight...

Simultaneous manipulation of multiple boundary conditions in nanoscale heterostructures offers a versatile route to stabilizing unusual structures and emergent phases. Here, we show that a stable supercrystal phase comprising a three-dimensional ordering of nanoscale domains with tailored periodicities can be engineered in PbTiO3–SrRuO3 ferroelectr...

During switching, the microstructure of a ferroelectric normally adapts to align internal dipoles with external electric fields. Favorably oriented dipolar regions (domains) grow at the expense of those in unfavorable orientations and this is manifested in a predictable field‐induced motion of the walls that separate one domain from the next. Here,...

Heavy reliance on extensively studied AlGaN based light emitting diodes (LEDs) to replace environmentally hazardous mercury based ultraviolet (UV) lamps is inevitable. However, external quantum efficiency (EQE) for AlGaN based deep UV emitters remains poor. Dislocation induced nonradiative recombination centers and poor electron-hole wavefunction o...

Ferroelectric domain wall (DW) based nano-electronics is an emerging new field of research. It is only recently with advancements in electron and atomic force microscopy instrumentation that the complex nature of these 2D entities can be probed. In this Research Update, the advances in aberration corrected scanning transmission electron microscopy...

Charged domain walls (DWs) in ferroelectric materials are an area of intense research. Microscale strain has been identified as a method of inducing arrays of twin walls to meet at right angles, forming needlepoint domains which exhibit novel material properties. Atomic scale characterisation of the features exhibiting these exciting behaviours was...

Multiferroic domain walls are an emerging solution for future low-power nanoelectronics due to their combined tuneable functionality and mobility. Here we show that the magnetoelectric multiferroic Aurivillius phase Bi6TixFeyMnzO18 (B6TFMO) crystal is an ideal platform for domain wall-based nanoelectronic devices. The unit cell of B6TFMO is distinc...

Multiferroic domain walls are an emerging solution for future low-power nanoelectronics due to their combined tuneable functionality and mobility. Here we show that the magnetoelectric multiferroic Aurivillius phase Bi6TixFeyMnzO18 (B6TFMO) crystal is an ideal platform for domain wall-based nanoelectronic devices. The unit cell of B6TFMO is distinc...

Multiferroic topologies are an emerging solution for future low-power magnetic nanoelectronics due to their combined tuneable functionality and mobility. Here, we show that in addition to being magnetoelectric multiferroic at room temperature, thin film Aurivillius phase Bi 6 Ti x Fe y Mn z O 18 is an ideal material platform for both domain wall an...

There has been a relentless pursuit of transverse electric (TE)-dominant deep ultraviolet (UV) optoelectronic devices for efficient surface emitters to replace the environmentally unfriendly mercury lamps. To date, the use of the ternary AlGaN alloy inevitably has led to transverse magnetic (TM)-dominant emission, an approach that is facing a roadb...

Charge Carriers in Dynamic Ferroelectric Domain Walls - Kalani Moore, Lynette Keeney, Clive Downing, Michele Conroy, Ursel Bangert

Probing the Dynamics of Topologically Protected Charged Ferroelectric Domain Walls with the Electron Beam at the Atomic Scale - Michele Conroy, Kalani Moore, Eoghan O'Connell, Lewys Jones, Clive Downing, Roger Whamore, Alexei Gruverman, Marty Gregg, Ursel Bangert

In-situ TEM Investigation of the Amorphous to Crystalline Phase Change During Electrical Breakdown of Highly Conductive Polymers at the Atomic Scale - Michele Conroy, Kalani Moore, Rob Lehane, Alonso Gamero-Quijano, Micheal Scanlon, Ursel Bangert

A domain wall‐enabled memristor is created, in thin film lithium niobate capacitors, which shows up to twelve orders of magnitude variation in resistance. Such dramatic changes are caused by the injection of strongly inclined conducting ferroelectric domain walls, which provide conduits for current flow between electrodes. Varying the magnitude of...

Vanadium dioxide (VO2) is an archetypal Mott material with a metal-insulator transition (MIT) near room temperature. In thin films, this transition is affected by substrate-induced strain but, as film thickness increases, the strain is gradually relaxed and the bulk properties are recovered. Epitaxial films of VO2 on (001)-oriented rutile titanium...

Ferroelectric materials, and more specifically ferroelectric domain walls (DWs) have become an area of intense research in recent years. Novel physical phenomena have been discovered at these nanoscale topological polarisation discontinuities by mapping out the polarisation in each atomic unit cell around the DW in a scanning transmission electron...

The combination of two active Li-ion materials (Ge and Sn) can result in improved conduction paths and higher capacity retention. Here we report; for the first time; the implementation of Ge1-xSnx alloy nanowires as anode materials for Li-ion batteries. Ge1-xSnx alloy nanowires have been successfully grown via vapor-liquid-solid (VLS) technique dir...

Growing III-nitride nanowires on 2D materials is advantageous as it effectively decouples the underlying growth substrate from the properties of the nanowires. As a relatively new family of 2D materials, MXenes are promising candidates as III-nitride nanowire nucleation layers capable of providing simultaneous transparency and conductivity. In this...

Domain wall nanoelectronics is a rapidly evolving field, which explores the diverse electronic properties of the ferroelectric domain walls for application in low‐dimensional electronic systems. One of the most prominent features of the ferroelectric domain walls is their electrical conductivity. Here, using a combination of scanning probe and scan...

Investigating Ferroelectric Domain and Domain Wall Dynamics at Atomic Resolution by TEM/STEM in situ Heating and Biasing - Volume 25 Supplement - Michele Conroy, Kalani Moore, Eoghan O'Connell, Eileen Courtney, Alan Harvey, Charlotte Cochard, Joseph Guy, Raymond McQuaid, Lewys Jones, Clive Downing, Roger Whatmore, Marty Gregg, Ursel Bangert

Atomic-Scale Characterization of Ferro-Electric Domains in Lithium Niobate-revealing the Electronic Properties of Domain Walls - Volume 25 Supplement - M Conroy, K Moore, EN O'Connell, JPV McConville, H Lu, P Chaudhary, A Lipatov, A Sinitskii, A Gruverman, JM Gregg, U Bangert

Rapid Fourier Masked Domain Mapping to Reveal Head to Head Charged Domain Walls in Lead Titanate - Volume 25 Supplement - K. Moore, U. Bangert, M. Conroy, E. O'Connell, J.M. Gregg