Investigating the coverage dependent behaviour of CO on Gd/Pt(111)

2016 ◽  
Vol 18 (43) ◽  
pp. 29732-29739 ◽  
Author(s):  
Elisabeth Therese Ulrikkeholm ◽  
Martin Hangaard Hansen ◽  
Jan Rossmeisl ◽  
Ib Chorkendorff
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Functional Theory ◽  
Dependent Behaviour

The coverage dependent behaviour of CO on a strained Pt surface has been studied using in ultra high vacuum and using density functional theory.

Unexpected high binding energy of CO2 on CH3NH3PbI3 lead-halide organic–inorganic perovskites via bicarbonate formation

2018 ◽  
Vol 54 (71) ◽  
pp. 9949-9952 ◽  
Author(s):  
M. T. Nayakasinghe ◽  
Yulun Han ◽  
N. Sivapragasam ◽  
Dmitri S. Kilin ◽  
U. Burghaus
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Density Functional ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Binding Energy ◽  
Functional Theory ◽  
Bicarbonate Formation ◽  
Kinetics Of ◽  
Lead Halide

The adsorption kinetics of CO2 was experimentally characterized in ultra-high vacuum (UHV). In addition, density functional theory (DFT) calculations were included.

scholarly journals Effect of H Adsorption on the Magnetic Properties of an Fe Island on a W(110) Surface

2019 ◽  
Author(s):  
Marko Melander ◽  
Hannes Jonsson
Keyword(s):  
Magnetic Properties ◽  
Data Storage ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Low Dimensional ◽  
Low Dimensional Materials

<p>Low-dimensional materials, such as ultrathin films, nanoislands and wires, are actively being researched due to their interesting magnetic properties and possible technological applications for example in high density data storage. Results of calculations of an Fe nanoisland on a W(110) support are presented here with particular focus on the effect of hydrogen adsorption on its magnetic properties. This is an important consideration since hydrogen is present even under ultra-high vacuum conditions. The calculations are based on density functional theory within the generalized gradient approximation. The adsorption of H atoms is found to strongly decrease the magnetic moment of the Fe atoms they are bound to, down to less than a half in some cases as compared with the clean Fe island. The results show that it may be important to take the presence of hydrogen into account in measurements of magnetic properties of nanoislands.</p>

scholarly journals Effect of H Adsorption on the Magnetic Properties of an Fe Island on a W(110) Surface

2019 ◽  
Author(s):  
Marko Melander ◽  
Hannes Jonsson
Keyword(s):  
Magnetic Properties ◽  
Data Storage ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Low Dimensional ◽  
Low Dimensional Materials

<p>Low-dimensional materials, such as ultrathin films, nanoislands and wires, are actively being researched due to their interesting magnetic properties and possible technological applications for example in high density data storage. Results of calculations of an Fe nanoisland on a W(110) support are presented here with particular focus on the effect of hydrogen adsorption on its magnetic properties. This is an important consideration since hydrogen is present even under ultra-high vacuum conditions. The calculations are based on density functional theory within the generalized gradient approximation. The adsorption of H atoms is found to strongly decrease the magnetic moment of the Fe atoms they are bound to, down to less than a half in some cases as compared with the clean Fe island. The results show that it may be important to take the presence of hydrogen into account in measurements of magnetic properties of nanoislands.</p>

First-principles insight into CO hindered agglomeration of Rh and Pt single atoms on ZrO2

2020 ◽  
Author(s):  
Minttu M. Kauppinen ◽  
Marko Melander ◽  
Karoliina Honkala
Keyword(s):  
First Principles ◽  
Density Functional ◽  
High Vacuum ◽  
Kinetic Stability ◽  
Ultra High Vacuum ◽  
Functional Theory ◽  
Single Atoms ◽  
Atomistic Thermodynamics ◽  
Using Data ◽  
Insight Into

<div><div><div><p>In this first-principles study we evaluate the thermodynamic and kinetic stability of Rh and Pt single-atoms (SAs) and subnano clusters on the monoclinic zirconia surface with and without a CO atmosphere. To address the kinetic stability and agglomeration of SAs to clusters and nanoparticles, a non-equilibrium nanothermodynamic approach is developed and parametrised using data computed with density functional theory. The bare subnano clusters are more stable than SA and become more so with increasing size, which means the agglomeration is always favoured. CO binds strongly to the single atoms and clusters, and our atomistic thermodynamics treatment indicates that some CO will be present even at ultra-high vacuum conditions. A CO atmosphere is shown to hinder cluster growth from SA, and is even capable of spontaneous cluster disintegration in the case of Pt clusters. Analysis of the CO stretching frequencies reveals that subnano clusters and single atoms should give peaks in the same region, and that using them to distinguish between surface species requires caution.</p></div></div></div>

Numerical Analysis of Sub-Atomic AFM Imaging in Ultra-High Vacuum: Coupling Quantum Mechanics With Continuum Dynamics

2011 ◽  
Author(s):  
C. Alan Wright ◽  
Santiago D. Solares
Keyword(s):  
Density Functional ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Computational Method ◽  
Tungsten Atom ◽  
Electronic Density ◽  
Functional Theory ◽  
Higher Harmonics ◽  
Afm Imaging ◽  
Continuum Dynamics

Recent reports of sub-atomic resolution AFM images acquired using transition metal tips have sparked debate within the AFM community. However, an in-depth theoretical feasibility study of this work has yet to be produced. We focus on the tungsten/graphite system investigated by Hembacher and coworkers [Science 305, 380–383 (2004)] in which experimental higher-harmonics images revealed four-leaf clover symmetry features within the tungsten atom diameter. The authors interpret these features as the footprint of four bonding lobes of increased charge density at the tip apex atom, thought to be caused by covalent-like bonding in the bulk. Here we present our development of a computational method ranging from density functional theory to continuum dynamics for simulating the imaging process. We find that four lobes of increased electronic density are indeed present for W(001) tips and demonstrate the ability of the chemical forces on the tip apex atom to produce higher harmonics images.

First-principles insight into CO hindered agglomeration of Rh and Pt single atoms on ZrO2

2020 ◽  
Author(s):  
Minttu M. Kauppinen ◽  
Marko Melander ◽  
Karoliina Honkala
Keyword(s):  
First Principles ◽  
Density Functional ◽  
High Vacuum ◽  
Kinetic Stability ◽  
Ultra High Vacuum ◽  
Functional Theory ◽  
Single Atoms ◽  
Atomistic Thermodynamics ◽  
Using Data ◽  
Insight Into

<div><div><div><p>In this first-principles study we evaluate the thermodynamic and kinetic stability of Rh and Pt single-atoms (SAs) and subnano clusters on the monoclinic zirconia surface with and without a CO atmosphere. To address the kinetic stability and agglomeration of SAs to clusters and nanoparticles, a non-equilibrium nanothermodynamic approach is developed and parametrised using data computed with density functional theory. The bare subnano clusters are more stable than SA and become more so with increasing size, which means the agglomeration is always favoured. CO binds strongly to the single atoms and clusters, and our atomistic thermodynamics treatment indicates that some CO will be present even at ultra-high vacuum conditions. A CO atmosphere is shown to hinder cluster growth from SA, and is even capable of spontaneous cluster disintegration in the case of Pt clusters. Analysis of the CO stretching frequencies reveals that subnano clusters and single atoms should give peaks in the same region, and that using them to distinguish between surface species requires caution.</p></div></div></div>

Doping effects on the geometric and electronic structure of tin clusters

2019 ◽  
Vol 21 (44) ◽  
pp. 24478-24488 ◽  
Author(s):  
Martin Gleditzsch ◽  
Marc Jäger ◽  
Lukáš F. Pašteka ◽  
Armin Shayeghi ◽  
Rolf Schäfer
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Beam Deflection ◽  
Functional Theory ◽  
Doping Effects ◽  
Depth Analysis ◽  
Trajectory Simulations

In depth analysis of doping effects on the geometric and electronic structure of tin clusters via electric beam deflection, numerical trajectory simulations and density functional theory.

What correlation effects are covered by density functional theory?

2000 ◽  
Vol 98 (20) ◽  
pp. 1639-1658 ◽  
Author(s):  
Yuan He, Jurgen Grafenstein, Elfi Kraka,
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Correlation Effects ◽  
Functional Theory
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