Amjad Al Taleb

ORCID: 0000-0002-1367-0439
Publications
Citations
Views
---
Saved
---
About
Contact & Profiles
Research Areas
  • Graphene research and applications
  • Advanced Chemical Physics Studies
  • Surface and Thin Film Phenomena
  • Thermal properties of materials
  • Topological Materials and Phenomena
  • 2D Materials and Applications
  • Diamond and Carbon-based Materials Research
  • Quantum and electron transport phenomena
  • Quantum, superfluid, helium dynamics
  • Physics of Superconductivity and Magnetism
  • Cold Atom Physics and Bose-Einstein Condensates
  • Semiconductor materials and devices
  • Quantum optics and atomic interactions
  • Ion-surface interactions and analysis
  • Chalcogenide Semiconductor Thin Films
  • Atomic and Molecular Physics
  • nanoparticles nucleation surface interactions
  • MXene and MAX Phase Materials
  • Chemical and Physical Properties of Materials
  • Catalytic Processes in Materials Science
  • Magnetic properties of thin films
  • Machine Learning in Materials Science
  • Spectroscopy and Laser Applications
  • Advanced Materials Characterization Techniques
  • Hydrogen Storage and Materials

Universidad Autónoma de Madrid
2016-2025

Madrid Institute for Advanced Studies
2018-2021

Fraunhofer Institute for Laser Technology
2017

Atomic Energy Commission of Syria
2010

The study of surface phonon dispersion curves is motivated by the quest for a detailed understanding forces between atoms at and in bulk. In case graphene, additional motivation comes from fact that thermal conductivity dominated contributions acoustic phonons, while optical properties are essential to understand Raman spectra. this article, we review recent progress made experimental determination graphene grown on several single-crystal metal surfaces. two main techniques usually employed...

10.1088/0953-8984/28/10/103005 article EN cc-by Journal of Physics Condensed Matter 2016-02-17

Abstract We have determined the electron–phonon interaction in type II Dirac semimetallic 1T-PdTe 2 by means of helium atom scattering. While is isostructural with 1T-PtTe , only former superconductor. The difference can be traced to substantially larger value coupling λ = 0.58, obtained from Debye-Waller attenuation He specular peak. With this and surface Debye temperature, Θ D 106.2 K, we figured out superconducting critical T c 1.83 K given BCS theory, which good agreement (1.95 ± 0.03)...

10.1038/s41699-021-00204-5 article EN cc-by npj 2D Materials and Applications 2021-02-23

We report an extensive structural characterization of the surface 1T-PtTe2 crystals by means helium atom scattering (HAS) and ultra-high resolution scanning tunnelling microscopy (STM). HAS reveals that this bi-dimensional presents a large corrugation (∼) in direction. The lattice constant PtTe2 derived from positions diffraction peaks up to fifth order was found be , agreement with STM x-ray measurements. This value remains unchanged temperature range between 90 580 K. These findings...

10.1088/2053-1583/ab6268 article EN 2D Materials 2019-12-16

Inelastic helium atom scattering (HAS) is suitable to determine low-energy (few meV) vibrations spatially localized on structures in the nanometer range. This illustrated for nanodomes that appear often graphene (Gr) epitaxially grown single crystal metal surfaces. The nature of inelastic losses observed Gr/Ru(0001) and Gr/Cu/Ru(0001) has been clarified by intercalation Cu below Gr monolayer, which decouples layer from Ru substrate changes substantially out-of-plane, flexural phonon...

10.1021/acs.nanolett.5b02887 article EN Nano Letters 2015-12-02

Tin diselenide (SnSe2) is a van der Waals semiconductor, which spontaneously forms subnanometric SnO2 skin once exposed to air. Here, by means of surface-science spectroscopies and density functional theory, we have investigated the charge redistribution at SnO2–SnSe2 heterojunction in both oxidative humid environments. Explicitly, find that work function pristine SnSe2 surface increases 0.23 0.40 eV upon exposure O2 air, respectively, with transfer reaching 0.56 e–/SnO2 between underlying...

10.1021/acs.jpclett.0c02616 article EN cc-by The Journal of Physical Chemistry Letters 2020-10-09

The interplay between substrate interactions and electron-phonon coupling in two-dimensional (2D) materials presents a significant challenge understanding controlling their electronic properties. Here, we present comparative study of the structural characteristics, phonon dynamics, bulk monolayer NbSe$_2$ on epitaxial bilayer graphene (BLG) using helium atom scattering (HAS). High-resolution diffraction reveals (9x9)0$^{\circ}$ superstructure within monolayer, commensurate with BLG lattice,...

10.48550/arxiv.2501.08140 preprint EN arXiv (Cornell University) 2025-01-14

The interplay between substrate interactions and electron–phonon coupling in two-dimensional (2D) materials presents a significant challenge understanding controlling their electronic properties. Here, we present comparative study of the structural characteristics, phonon dynamics, bulk monolayer NbSe2 on epitaxial bilayer graphene (BLG) using helium atom scattering (HAS). High-resolution diffraction reveals (9 × 9)0° superstructure within monolayer, commensurate with BLG lattice, while...

10.1021/acsnano.4c16399 article EN cc-by ACS Nano 2025-02-26

We have studied the (0001) surface of 2H-MoS2 by means helium-atom scattering (HAS). The electron–phonon coupling constant, λ, this system has been determined measuring thermal attenuation specular peak at temperatures between 100 and 500 K. HAS diffraction also reveals a 3% planar dilation layer, whereas step interference measured low incidence energy indicates slight contraction layer thickness. By employing recently developed quantum-theoretical approach applied to case layered degenerate...

10.1021/acs.jpcc.8b12029 article EN The Journal of Physical Chemistry C 2019-01-19

We present angle- and energy-resolved analysis of Ne scattering from a Ni(111) surface at moderate beam energy temperature. Variation the temperature allows transition pure quantum regime, where single-phonon events are observed, to classical multiphonon excitations observed. The latter can be reproduced by calculations. Therefore, our data lie on border between coherent regime incoherent regime.

10.1103/physrevb.95.075414 article EN Physical review. B./Physical review. B 2017-02-10

We report helium diffraction from natural MoS2 single crystal. The high quality of the samples studied lead to appearance sharp and intense in-plane out-of-plane peaks, with unusually low background. pronounced features observed confirm corrugation 2D surface unit cell. observation along two main symmetry directions allows determining lattice constant accuracy. measured is Å. Within experimental error, parameter was found remain in temperature range between 90 522 K, good agreement...

10.1088/2053-1583/aabe4a article EN 2D Materials 2018-04-16

The development of novel reflective optical elements is essential to improve the focusing neutral atomic beams. recent availability commercial thin crystals led a renewed interest in curved mirrors as for He microscopy. We have investigated reflectivity incoming atoms Cu(111), Ni(111), and Ru(0001) thickness between 50 150 $\ensuremath{\mu}\mathrm{m}$. results been compared with ones obtained from bulk crystal surfaces. Our study reveals that 100 $\ensuremath{\mu}\mathrm{m}$ thick Cu(111)...

10.1103/physrevb.95.205428 article EN Physical review. B./Physical review. B 2017-05-22

Diffraction with matter waves has been reported since the beginning of quantum mechanics. In free space, diffraction effects have observed even objects as large C60 molecules. However, in scattering from a solid surface, pure elastic features never molecules larger than D2. Here we report observation molecular for CH4 scattered off an Ir(111) surface. These results prove that coherence is preserved, despite small separation between rotational levels and interaction surface phonons. Density...

10.1021/acs.jpclett.9b00158 article EN The Journal of Physical Chemistry Letters 2019-03-11

Using a reactive molecular beam with high kinetic energy ( E kin ), it is possible to speed gas–surface reactions involving activation barriers act which would require elevated pressures if random gas used.

10.1039/d3cp05071h article EN cc-by-nc Physical Chemistry Chemical Physics 2023-12-04

We have measured high-resolution angular distributions of methane scattered from a Ni(111) surface at incident energies between 68.9 meV and 108.6 meV. A sharp intense specular peak has been observed, in addition to features corresponding rotationally inelastic diffraction (RID) peaks along the two main symmetry directions Ni(111). The intensity most RID is ca. 50% one. observation sharp, coherent elastic such low suggests that single scattering dominates over trapping these energies, depth...

10.1039/c7cp04559j article EN Physical Chemistry Chemical Physics 2017-01-01

We show that neutral atom scattering is suitable to determine the coupling strength between a two-dimensional (2D) material and underlying substrate. This information can be obtained from thermal attenuation of specular intensity, as well angular distributions He Ne atoms in low incident energy (∼50 meV) regime. For graphene (Gr) grown on several metal substrates, there direct correlation slope measurements Gr–substrate surface phonons measurements. In addition, presents broad, classical...

10.1088/2053-1583/aacf26 article EN 2D Materials 2018-06-26

We report Ne atom scattering from clean Ru(0001) and covered with a single layer of graphene. For both systems, the quantum classical regimes are observed analyzed. The to boundary is explored by varying surface temperature incident kinetic energy. smooth model used perform theoretical simulations in order reproduce angular distributions regime determine effective mass hence allow determination Debye temperature. calculations, agreement experiments, predict that subspecular at low energies...

10.1021/acs.jpcc.7b07042 article EN The Journal of Physical Chemistry C 2017-10-03

Abstract Closed-shell atoms scattered from a metal surface exchange energy and momentum with phonons mostly via the interposed valence electrons, i.e., creation of virtual electron-hole pairs. The latter can then decay into electron-phonon interaction, as well acoustic plasmons (ASPs). While first channel is basis current inelastic atom scattering (IAS) surface-phonon spectroscopy, no attempt to observe ASPs IAS has been made so far. In this study we provide evidence ASP in Ni(111) both Ne...

10.1038/s41598-021-81018-9 article EN cc-by Scientific Reports 2021-01-15

The ability of the different approaches proposed to date include effects van der Waals (vdW) dispersion forces in density functional theory (DFT) is currently under debate. Here, we used diffraction He on a Ru(0 0 1) surface as challenging benchmark system analyze suitability several representative approaches, from ones correcting exchange-correlation generalized gradient approximation (GGA) functional, DFT energies through pairwise-based methods. To perform our analysis, have built seven...

10.1088/1361-648x/aafcfd article EN Journal of Physics Condensed Matter 2019-01-09

The fabrication of atomically smooth metal films on supporting oxides is a quite demanding task, since most physical vapor deposition methods used metals do not work properly oxide substrates. Here, we report an alternative procedure, based performing laser polishing fused silica substrate before depositing the metallic thin film. This reduces RMS surface roughness by ca. 33%, and increases maximum grain size film from 200 nm to 1200 nm. method has been applied parabolic lens, which coated...

10.1063/1.4999917 article EN Applied Physics Letters 2017-10-30

We present an experimental study of the initial dissociative sticking probability H2 on Pd–Cu(111) surface alloy at Pd coverages between 1–10%. The measurements have been performed using a supersonic molecular beam with incident energy range Ei = 75–163 meV. In agreement recent STM study, our results confirm that small amounts atoms significantly increase reactivity inert Cu(111) surface, although measured values were found to be much lower than ones estimated from work. For coverage 1% and...

10.1524/zpch.2013.0392 article EN Zeitschrift für Physikalische Chemie 2013-01-01
Coming Soon ...