Methane dehydrogenation on Cu and Ni surfaces with low and moderate oxygen coverage

2019 ◽  
Vol 120 (2) ◽  
Author(s):  
Behnaz Rahmani Didar ◽  
Perla B. Balbuena
Keyword(s):  
Oxygen Coverage

Oxygen Coverage Effect on the Magnetic Properties of the Cr2NOx (0 ≤ x ≤ 2) MXene

2021 ◽  
Author(s):  
Rodrigo Ponce-Pérez ◽  
Jonathan Guerrero-Sanchez ◽  
Sandra J. Gutierrez-Ojeda ◽  
María G. Moreno-Armenta
Keyword(s):  
Magnetic Properties ◽  
Oxygen Coverage

scholarly journals Large Dzyaloshinskii-Moriya interaction induced by chemisorbed oxygen on a ferromagnet surface

2020 ◽  
Vol 6 (33) ◽  
pp. eaba4924 ◽  
Author(s):  
Gong Chen ◽  
Arantzazu Mascaraque ◽  
Hongying Jia ◽  
Bernd Zimmermann ◽  
MacCallum Robertson ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ferromagnetic Layer ◽  
Spin Orbit Coupling ◽  
Winding Number ◽  
Large Magnitude ◽  
Chemisorbed Oxygen ◽  
Magnetic Layers ◽  
Oxygen Coverage ◽  
Opening Up ◽  
Moriya Interaction

The Dzyaloshinskii-Moriya interaction (DMI) is an antisymmetric exchange interaction that stabilizes chiral spin textures. It is induced by inversion symmetry breaking in noncentrosymmetric lattices or at interfaces. Recently, interfacial DMI has been found in magnetic layers adjacent to transition metals due to the spin-orbit coupling and at interfaces with graphene due to the Rashba effect. We report direct observation of strong DMI induced by chemisorption of oxygen on a ferromagnetic layer at room temperature. The sign of this DMI and its unexpectedly large magnitude—despite the low atomic number of oxygen—are derived by examining the oxygen coverage–dependent evolution of magnetic chirality. We find that DMI at the oxygen/ferromagnet interface is comparable to those at ferromagnet/transition metal interfaces; it has enabled direct tailoring of skyrmion’s winding number at room temperature via oxygen chemisorption. This result extends the understanding of the DMI, opening up opportunities for the chemisorption-related design of spin-orbitronic devices.

Energetic Studies on the B Effect on the Oxidation of γ-TiAl Alloys

2014 ◽  
Vol 1052 ◽  
pp. 28-33 ◽  
Author(s):  
Guo Ying Zhang ◽  
Gui Li Liu ◽  
Jun Shan Bao ◽  
Chun Ming Liu ◽  
Hui Zhang
Keyword(s):  
Oxide Film ◽  
First Principles ◽  
Density Functional ◽  
Oxidation Process ◽  
Interstitial Site ◽  
Initial Oxidation ◽  
Functional Theory ◽  
Tial Alloys ◽  
Surface And Interface ◽  
Oxygen Coverage

The energetic study of B effects on the oxidation of γ-TiAl alloys are performed by using the first-principles method based on Density Functional Theory (DFT) in this paper. The surface and interface segregatation of B as well as of the surface adsorption of O are discussed. B is found to preferentially segregat to TiAl subsurface with respect to γ-TiAl bulk. The B segregation at surface decreases oxygen coverage in the initial oxidation process of γ –TiAl alloys, thereby it is beneficial to the decrease of the growth of γ–TiAl alloys oxide film. In the initial oxidation process, oxygen prefers to stay in the vicinity of surface Ti atoms, and B addition is beneficial for the decrease of the growth of A12O3 and TiO2. After the formation of Al2O3 oxide film, B is energetically favoured stayed at interstitial site of α-Al2O3 (0001)/γ-TiAl (111) interface, and enhances the adhesion of this interface.

Differentiation of catalytic sites by oxygen coverage measurements

1984 ◽  
Vol 21 (4) ◽  
pp. 335-346
Author(s):  
Thomas C. Franklin ◽  
Hiroshi Kagawa
Keyword(s):  
Catalytic Sites ◽  
Oxygen Coverage

Effects of chlorine and oxygen coverage on the structure of the Au(111) surface

2009 ◽  
Vol 130 (8) ◽  
pp. 084701 ◽  
Author(s):  
Thomas A. Baker ◽  
Cynthia M. Friend ◽  
Efthimios Kaxiras
Keyword(s):  
Oxygen Coverage

Chemical Restructuring of Metal Surfaces Studied by Scanning Tunneling Microscope (STM)

1997 ◽  
Vol 3 (S2) ◽  
pp. 577-578
Author(s):  
Ken-ichi Tanaka
Keyword(s):  
Scanning Tunneling Microscope ◽  
Metal Surfaces ◽  
Substrate Surface ◽  
Critical Value ◽  
Dissociative Adsorption ◽  
The Other ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Oxygen Coverage ◽  
Nano Size

Metal surfaces undergo structural change by the dissociative adsorption of O2, where the reconstructuring is caused by either of the two distinctive mechanisms depending on the temperature and/or the crystalographic planes, one is the “adsorption induced reconstruction” and the other is the “formation of quasi-compounds and their array over the surface”.The oxygen induced reconstruction of Cu(100) is the former case. When a Cu(100) surface is exposed to O2, oxygen atoms are adsored by making nano-size c(2x2) structure to avoid the convergence of the stress induced by the adsorption. When the oxygen coverage exceeds a critical value of ca 0.3 ML, Cu atoms are missed from the substrate surface to release the stress and the R45 reconstruction is established. In contrast to the Cu(l00) surface, an entirely different process takes place on a Cu( 110) surface exposed to O2, where the (-Cu-O-) string is formed and by a chemical array over the terrace occur.

scholarly journals Kinetic Barriers of the Phase Transition in the Oxygen Chemisorbed Cu(110)-(2 × 1)-O as a Function of Oxygen Coverage

2014 ◽  
Vol 118 (36) ◽  
pp. 20858-20866 ◽  
Author(s):  
Liang Li ◽  
Qianqian Liu ◽  
Jonathan Li ◽  
Wissam A. Saidi ◽  
Guangwen Zhou
Keyword(s):  
Phase Transition ◽  
Oxygen Coverage ◽  
Kinetic Barriers
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