Spectroscopic Observation and Molecular Dynamics Simulation of Ga Surface Segregation in Liquid Pd-Ga Alloys

Journal article


Publication Details

Author(s): Grabau M, Erhard J, Taccardi N, Krick Calderon S, Wasserscheid P, Görling A, Steinrück HP, Papp C
Journal: Chemistry - A European Journal
Publisher: WILEY-V C H VERLAG GMBH
Publication year: 2017
Volume: 23
Journal issue: 70
Pages range: 17701-17706
ISSN: 0947-6539
Language: English


Abstract


Liquid binary Pd-Ga alloys with low Pd contents of 0.8, 1.8, and 4.7at% of Pd were examined as a function of sample temperature in ultra-high vacuum by using angle-resolved XPS. Upon cooling from 750 to 400K, a pronounced temperature-dependence of the Pd concentration in the liquid phase was observed, which was explained by the transition from the pure liquid phase to a two-phase system, consisting of a solid Ga5Pd phase and a Pd-depleted liquid Pd-Ga alloy. In the liquid Pd-Ga alloy, Pd is always depleted from the topmost interface layer, as deduced from angle-resolved XPS at 0 and 80 degrees emission, independent of temperature and Pd concentration. This observation is interpreted as an inhomogeneous depth distribution function of Pd, that is, the segregation of Ga to the surface of the liquid phase. The results of a DFT-based molecular dynamics simulation (MD) independently show interfacial stratification of Ga and an inhomogeneous Pd distribution along the surface normal. The evaluation of the experimental data with a rigid layer model based on the MD calculations leads to excellent agreement with the simulation.



FAU Authors / FAU Editors

Erhard, Jannis
Lehrstuhl für Theoretische Chemie
Görling, Andreas Prof. Dr.
Lehrstuhl für Theoretische Chemie
Grabau, Mathias Dr.
Lehrstuhl für Physikalische Chemie II
Krick Calderon, Sandra
Lehrstuhl für Physikalische Chemie II
Papp, Christian PD Dr.
Lehrstuhl für Physikalische Chemie II
Steinrück, Hans-Peter Prof. Dr.
Lehrstuhl für Physikalische Chemie II
Taccardi, Nicola Dr.
Lehrstuhl für Chemische Reaktionstechnik
Wasserscheid, Peter Prof. Dr.
Lehrstuhl für Chemische Reaktionstechnik


Additional Organisation
Exzellenz-Cluster Engineering of Advanced Materials


Research Fields

D Catalytic Materials
Exzellenz-Cluster Engineering of Advanced Materials
A3 Multiscale Modeling and Simulation
Exzellenz-Cluster Engineering of Advanced Materials


How to cite

APA:
Grabau, M., Erhard, J., Taccardi, N., Krick Calderon, S., Wasserscheid, P., Görling, A.,... Papp, C. (2017). Spectroscopic Observation and Molecular Dynamics Simulation of Ga Surface Segregation in Liquid Pd-Ga Alloys. Chemistry - A European Journal, 23(70), 17701-17706. https://dx.doi.org/10.1002/chem.201703627

MLA:
Grabau, Mathias, et al. "Spectroscopic Observation and Molecular Dynamics Simulation of Ga Surface Segregation in Liquid Pd-Ga Alloys." Chemistry - A European Journal 23.70 (2017): 17701-17706.

BibTeX: 

Last updated on 2018-11-08 at 03:14