Search Results

You searched for all publications:

with publication states 'Published (Approved)'
published in journal 'Nano Letters'

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

Exact matches
Related results

39 items found (0 items not approved), displaying 1 to 10.[First/Prev] 1, 2, 3, 4 [Next/Last]

Instruments / Technical Area	Publication Details	Published
I05-ARPES	Direct visualization of subnanometer variations in the excitonic spectra of 2D/3D semiconductor/metal heterostructures Kate Reidy , Paulina Ewa Majchrzak , Benedikt Haas , Joachim Dahl Thomsen , Andrea Konečná , Eugene Park , Julian Klein , Alfred J. H. Jones , Klara Volckaert , Deepnarayan Biswas , Matthew D. Watson , Cephise Cacho , Prineha Narang , Christoph T. Koch , Soeren Ulstrup , Frances M. Ross , Juan Carlos Idrobo Nano Letters DOI: 10.1021/acs.nanolett.2c04749 Diamond Proposal Number(s): [25368, 29607] Show Abstract ▼ Abstract: The integration of metallic contacts with two-dimensional (2D) semiconductors is routinely required for the fabrication of nanoscale devices. However, nanometer-scale variations in the 2D/metal interface can drastically alter the local optoelectronic properties. Here, we map local excitonic changes of the 2D semiconductor MoS2 in contact with Au. We utilize a suspended and epitaxially grown 2D/metal platform that allows correlated electron energy-loss spectroscopy (EELS) and angle resolved photoelectron spectroscopy (nanoARPES) mapping. Spatial localization of MoS2 excitons uncovers an additional EELS peak related to the MoS2/Au interface. NanoARPES measurements indicate that Au–S hybridization decreases substantially with distance from the 2D/metal interface, suggesting that the observed EELS peak arises due to dielectric screening of the excitonic Coulomb interaction. Our results suggest that increasing the van der Waals distance could optimize excitonic spectra of mixed-dimensional 2D/3D interfaces and highlight opportunities for Coulomb engineering of exciton energies by the local dielectric environment or moiré engineering.	Jan 2023
I09-Surface and Interface Structural Analysis	Spontaneous lithiation of binary oxides during epitaxial growth on LiCoO2 Le Wang , Zhenzhong Yang , Widitha S. Samarakoon , Yadong Zhou , Mark E. Bowden , Hua Zhou , Jinhui Tao , Zihua Zhu , Nabajit Lahiri , Timothy C. Droubay , Zachary W. Lebens-Higgins , Xinmao Yin , Chi Sin Tang , Zhenxing Feng , Louis F. J. Piper , Andrew T. S. Wee , Scott A. Chambers , Yingge Du Nano Letters 9 DOI: 10.1021/acs.nanolett.2c01701 Diamond Proposal Number(s): [19162] Show Abstract ▼ Abstract: Epitaxial growth is a powerful tool for synthesizing heterostructures and integrating multiple functionalities. However, interfacial mixing can readily occur and significantly modify the properties of layered structures, particularly for those containing energy storage materials with smaller cations. Here, we show a two-step sequence involving the growth of an epitaxial LiCoO2 cathode layer followed by the deposition of a binary transition metal oxide. Orientation-controlled epitaxial synthesis of the model solid-state-electrolyte Li2WO4 and anode material Li4Ti5O12 occurs as WO3 and TiO2 nucleate and react with Li ions from the underlying cathode. We demonstrate that this lithiation-assisted epitaxy approach can be used for energy materials discovery and exploring different combinations of epitaxial interfaces that can serve as well-defined model systems for mechanistic studies of energy storage and conversion processes.	Jun 2022
E02-JEM ARM 300CF	Atomic-level dynamics of point vacancies and the induced stretched defects in 2D monolayer PtSe2 Jun Chen , Jiang Zhou , Wenshuo Xu , Yi Wen , Yuanyue Liu , Jamie H. Warner Nano Letters DOI: 10.1021/acs.nanolett.1c04275 Diamond Proposal Number(s): [22549] Show Abstract ▼ Abstract: Monolayer PtSe2 holds great potential in extending 2D devices functionality, but their atomic-level-defect study is still limited. Here, we investigate the atomic structures of lattice imperfections from point to stretched 1D defects in 1T-PtSe2 monolayers, using annular dark-field scanning transmission electron microscopy (ADF-STEM). We show Se vacancies (VSe) have preferential sites with high beam-induced mobility. Diverse divacancies form with paired VSe. We found stretched linear defects triggered by dynamics of VSe that altered strain fields, distinct from the line vacancies in 2H-phase 2D materials. The paired VSe stability and formation possibility of vacancy lines are evaluated by density functional theory. Lower sputtering energy in PtSe2 than that in MoS2 can cause larger possibility of atomic loss compared to diffusion required for creating VSe lines. This provides atomic insights into the defects in 1T-PtSe2 and shows how a deviated 1D structure is embedded in a 2D system without losing atom lines.	Apr 2022
B18-Core EXAFS	The influence of defects on the luminescence of trivalent terbium in nanocrystalline yttrium orthovanadate Rafael Vieira Perrella , Marc Walker , Thomas Chamberlain , Richard Walton , Paulo Cesar De Sousa Filho Nano Letters 22 DOI: 10.1021/acs.nanolett.1c04937 Diamond Proposal Number(s): [14239] Show Abstract ▼ Abstract: Terbium-doped YVO4 has been considered a nonluminescent solid since the first classic studies on rare-earth-doped phosphors in the 1960s. However, we demonstrate that defect engineering of YVO4:Tb3+ nanoparticles overcomes the metal–metal charge transfer (MMCT) process which is responsible for the quenching of the Tb3+ luminescence. Tetragonal (Y1–xTbx)VO4 nanoparticles obtained by colloidal precipitation showed expanded unit cells, high defect densities, and intimately mixed carbonates and hydroxides, which contribute to a shift of the MMCT states to higher energies. Consequently, we demonstrate unambiguously for the first time that Tb3+ luminescence can be excited by VO43– → Tb3+ energy transfer and by direct population of the 5D4 state in YVO4. We also discuss how thermal treatment removes these effects and shifts the quenching MMCT state to lower energies, thus highlighting the major consequences of defect density and microstructure in nanosized phosphors. Therefore, our findings ultimately show nanostructured YVO4:Tb3+ can be reclassified as a UV-excitable luminescent material.	Apr 2022
I10-Beamline for Advanced Dichroism	Axially bound magnetic skyrmions: glueing topological strings across an interface Kejing Ran , Yizhou Liu , Haonan Jin , Yanyan Shangguan , Yao Guang , Jinsheng Wen , Guoqiang Yu , Gerrit Van Der Laan , Thorsten Hesjedal , Shilei Zhang Nano Letters 68 DOI: 10.1021/acs.nanolett.2c00689 Diamond Proposal Number(s): [26148] Open Access Show Abstract ▼ Abstract: A major challenge in topological magnetism lies in the three-dimensional (3D) exploration of their magnetic textures. A recent focus has been the question of how 2D skyrmion sheets vertically stack to form distinct types of 3D topological strings. Being able to manipulate the vertical coupling should therefore provide a route to the engineering of topological states. Here, we present a new type of axially bound magnetic skyrmion string state in which the strings in two distinct materials are glued together across their interface. With quasi-tomographic resonant elastic X-ray scattering, the 3D skyrmion profiles before and after their binding across the interface were unambiguously determined and compared. Their attractive binding is accompanied by repulsive twisting; i.e., the coupled skyrmions mutually affect each other via a compensating twisting. This state exists in chiral magnet–magnetic thin film heterostructures, providing a new arena for the engineering of 3D topological phases.	Apr 2022
I10-Beamline for Advanced Dichroism	Transition metal synthetic ferrimagnets: Tunable media for all-optical switching driven by nanoscale spin current Maciej Dabrowski , Jade N. Scott , William R. Hendren , Colin M. Forbes , Andreas Frisk , David Burn , David G. Newman , Connor R. J. Sait , Paul S. Keatley , Alpha T. N'Diaye , Thorsten Hesjedal , Gerrit Van Der Laan , Robert Bowman , Robert J. Hicken Nano Letters DOI: 10.1021/acs.nanolett.1c03081 Diamond Proposal Number(s): [17745, 19116, 20760] Show Abstract ▼ Abstract: All-optical switching of magnetization has great potential for use in future ultrafast and energy efficient nanoscale magnetic storage devices. So far, research has been almost exclusively focused on rare-earth based materials, which limits device tunability and scalability. Here, we show that a perpendicularly magnetized synthetic ferrimagnet composed of two distinct transition metal ferromagnetic layers, Ni3Pt and Co, can exhibit helicity independent magnetization switching. Switching occurs between two equivalent remanent states with antiparallel alignment of the Ni3Pt and Co magnetic moments and is observable over a broad temperature range. Time-resolved measurements indicate that the switching is driven by a spin-polarized current passing through the subnanometer Ir interlayer. The magnetic properties of this model system may be tuned continuously via subnanoscale changes in the constituent layer thicknesses as well as growth conditions, allowing the underlying mechanisms to be elucidated and paving the way to a new class of data storage devices.	Oct 2021
	Crystal structure of colloidally prepared metastable Ag2Se nanocrystals Bryce A. Tappan , Bonan Zhu , Patrick Cottingham , Matthew Mecklenburg , David O. Scanlon , Richard L. Brutchey Nano Letters DOI: 10.1021/acs.nanolett.1c02045 Show Abstract ▼ Abstract: Structural polymorphism is known for many bulk materials; however, on the nanoscale metastable polymorphs tend to form more readily than in the bulk, and with more structural variety. One such metastable polymorph observed for colloidal Ag2Se nanocrystals has traditionally been referred to as the “tetragonal” phase. While there are reports on the chemistry and properties of this metastable polymorph, its crystal structure, and therefore electronic structure, has yet to be determined. We report that an anti-PbCl2-like structure type (space group P21/n) more accurately describes the powder X-ray diffraction and X-ray total scattering patterns of colloidal Ag2Se nanocrystals prepared by several different methods. Density functional theory (DFT) calculations indicate that this anti-PbCl2-like Ag2Se polymorph is a dynamically stable, narrow-band-gap semiconductor. The anti-PbCl2-like structure of Ag2Se is a low-lying metastable polymorph at 5–25 meV/atom above the ground state, depending on the exchange-correlation functional used.	Jul 2021
I12-JEEP: Joint Engineering, Environmental and Processing	Strain-stabilized (π, π) order at the surface of Fe1+xTe Chi Ming Yim , Soumendra Nath Panja , Christopher Trainer , Craig Topping , Christoph Heil , Alexandra S. Gibbs , Oxana Magdysyuk , Vladimir Tsurkan , Alois Loidl , Andreas W. Rost , Peter Wahl Nano Letters DOI: 10.1021/acs.nanolett.0c04821 Diamond Proposal Number(s): [22974] Open Access Show Abstract ▼ Abstract: A key property of many quantum materials is that their ground state depends sensitively on small changes of an external tuning parameter, e.g., doping, magnetic field, or pressure, creating opportunities for potential technological applications. Here, we explore tuning of the ground state of the nonsuperconducting parent compound, Fe1+xTe, of the iron chalcogenides by uniaxial strain. Iron telluride exhibits a peculiar (π, 0) antiferromagnetic order unlike the (π, π) order observed in the Fe-pnictide superconductors. The (π, 0) order is accompanied by a significant monoclinic distortion. We explore tuning of the ground state by uniaxial strain combined with low-temperature scanning tunneling microscopy. We demonstrate that, indeed under strain, the surface of Fe1.1Te undergoes a transition to a (π, π)-charge-ordered state. Comparison with transport experiments on uniaxially strained samples shows that this is a surface phase, demonstrating the opportunities afforded by 2D correlated phases stabilized near surfaces and interfaces.	Apr 2021
	Oleylamine aging of PtNi nanoparticles giving enhanced functionality for the oxygen reduction reaction Gerard M. Leteba , Yi-Chi Wang , Thomas J. A. Slater , Rongsheng Cai , Conor Byrne , Christopher P. Race , David R. G. Mitchell , Pieter B. J. Levecque , Neil P. Young , Stuart M. Holmes , Alex Walton , Angus I. Kirkland , Sarah J. Haigh , Candace I. Lang Nano Letters DOI: 10.1021/acs.nanolett.1c00706 Open Access Show Abstract ▼ Abstract: We report a rapid solution-phase strategy to synthesize alloyed PtNi nanoparticles which demonstrate outstanding functionality for the oxygen reduction reaction (ORR). This one-pot coreduction colloidal synthesis results in a monodisperse population of single-crystal nanoparticles of rhombic dodecahedral morphology with Pt-enriched edges and compositions close to Pt1Ni2. We use nanoscale 3D compositional analysis to reveal for the first time that oleylamine (OAm)-aging of the rhombic dodecahedral Pt1Ni2 particles results in Ni leaching from surface facets, producing aged particles with concave faceting, an exceptionally high surface area, and a composition of Pt2Ni1. We show that the modified atomic nanostructures catalytically outperform the original PtNi rhombic dodecahedral particles by more than two-fold and also yield improved cycling durability. Their functionality for the ORR far exceeds commercially available Pt/C nanoparticle electrocatalysts, both in terms of mass-specific activities (up to a 25-fold increase) and intrinsic area-specific activities (up to a 27-fold increase).	Apr 2021
I04-1-Macromolecular Crystallography (fixed wavelength)	Nanoscale pattern extraction from relative positions of sparse 3D localizations Alistair P. Curd , Joanna Leng , Ruth E. Hughes , Alexa J. Cleasby , Brendan Rogers , Chi H. Trinh , Michelle A. Baird , Yasuharu Takagi , Christian Tiede , Christian Sieben , Suliana Manley , Thomas Schlichthaerle , Ralf Jungmann , Jonas Ries , Hari Shroff , Michelle Peckham Nano Letters DOI: 10.1021/acs.nanolett.0c03332 Diamond Proposal Number(s): [15378] Show Abstract ▼ Abstract: Inferring the organization of fluorescently labeled nanosized structures from single molecule localization microscopy (SMLM) data, typically obscured by stochastic noise and background, remains challenging. To overcome this, we developed a method to extract high-resolution ordered features from SMLM data that requires only a low fraction of targets to be localized with high precision. First, experimentally measured localizations are analyzed to produce relative position distributions (RPDs). Next, model RPDs are constructed using hypotheses of how the molecule is organized. Finally, a statistical comparison is used to select the most likely model. This approach allows pattern recognition at sub-1% detection efficiencies for target molecules, in large and heterogeneous samples and in 2D and 3D data sets. As a proof-of-concept, we infer ultrastructure of Nup107 within the nuclear pore, DNA origami structures, and α-actinin-2 within the cardiomyocyte Z-disc and assess the quality of images of centrioles to improve the averaged single-particle reconstruction.	Nov 2020

Publications Database

Search Results

You searched for all publications:

Search Again...

Subject Areas (check all that apply) select all

Instruments used to collect data (check all that apply) select all

Collaborations involved (check all that apply) select all

Diamond Offline Facilities used

Relevant Technical Areas (check all that apply) select all

Menu for Anonymous User