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Events
Event Date: March 12, 2018

March 12-15, 2018 Berlin, Germany
2018 Joint Meeting of the DPG and EPS Condensed Matter Divisions
The conference will be held at the Technical University of Berlin in Berlin, Germany

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Event Date: March 6, 2018

March 6-8, 2018 Los Angeles, California, USA
American Physical Society March Meeting 2018
The conference will be held in the Los Angeles Convention Center in Los Angeles, CA, USA

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Image of the Month
Posted Date: January 16, 2018

Reference:
The Journal of Chemical Physics 147, 044704 (2017); doi: 10.1063/1.4995598

FIG. 1. STM images of (a) pure Au (1.0 MLe), (b) Au (1.0 MLe) and subsequently Rh (1.0 MLe), (c) pure Rh (1.0 MLe), (d) Rh (1.0 MLe) and subsequently Au (0.2 MLe) deposited on thin-film Al2O3/NiAl(100) at 300 K. The insets of each figure show histograms of diameters and heights of the clusters. The grey bars in the histograms of (b) and (d) correspond to the STM images and the red bars are from those of (a) and (c), respectively, shown side by side to demonstrate the variation of the size distribution.

FIG. 1. STM images of (a) pure Au (1.0 MLe), (b) Au (1.0 MLe) and subsequently Rh (1.0 MLe), (c) pure Rh (1.0 MLe), (d) Rh (1.0 MLe) and subsequently Au (0.2 MLe) deposited on thin-film Al2O3/NiAl(100) at 300 K. The insets of each figure show histograms of diameters and heights of the clusters. The grey bars in the histograms of (b) and (d) correspond to the STM images and the red bars are from those of (a) and (c), respectively, shown side by side to demonstrate the variation of the size distribution.

Abstract
The surface structures and compositions of Au–Rh bimetallic nanoclusters on an ordered thin film of Al2O3/NiAl(100) were investigated, primarily with infrared reflection absorption spectra and temperature-programmed desorption of CO as a probe molecule under ultrahigh-vacuum conditions and calculations based on density-functional theory. The bimetallic clusters were formed by sequen- tial deposition of vapors of Au and Rh onto Al2O3/NiAl(100) at 300 K. Alloying in the clusters was active and proceeded toward a specific structure—a fcc phase, (100) orientation, and Rh core-Au shell structure, regardless of the order of metal deposition. For Au clusters incorporating deposited Rh, the Au atoms remained at the cluster surface through position exchange and became less coordinated; for deposition in reverse order, deposited Au simply decorated the surfaces of Rh clusters. Both adsorption energy and infrared absorption intensity were enhanced for CO on Au sites of the bimetallic clusters; both of them are associated with the bonding to Rh and also a decreased coordination number of CO- binding Au. These enhancements can thus serve as a fingerprint for alloying and atomic inter-diffusion in similar bimetallic systems.

Reference:
The Journal of Chemical Physics 147, 044704 (2017); doi: 10.1063/1.4995598

Credits:
Hsuan Lee,1 Zhen-He Liao,1 Po-Wei Hsu,1 Ting-Chieh Hung,1 Yu-Cheng Wu,1 Yuwei Lin,2 Jeng-Han Wang,2,a) and Meng-Fan Luo1,a)

1 Department of Physics, National Central University, 300 Jhongda Road, Taoyuan 32001, Taiwan

2 Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan 

a) Authors to whom correspondence should be addressed: [email protected] edu.tw and [email protected]

Microscope:
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Panscan Freedom SPM,  VT Beetle
Events
Event Date: January 14, 2018

January 14, 2018
PCSI-45 – 45th Conference on the Physics & Chemistry of Surfaces & Interfaces
The Conference will be held at the Sheraton Kona Resort in Kona, Hawaii, USA
https://pcsi2018.avs.org/

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