Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surfaces and Interfaces

26.11.2010
Innovative techniques allow researchers to study interfaces with great precision. The methods could become powerful tools in the rational design of catalytic materials

Equipment built by German scientists can be used to study processes at interfaces with great accuracy. In an article published recently in ChemPhysChem, Hans Joachim Freund and co-workers of the Fritz-Haber-Institut in Berlin describe the advancement of four experimental techniques developed in their lab to investigate nanoscopic systems.

By combining photon scanning tunneling microscopy, aberration-corrected low-energy electron microscopy coupled to photoelectron emission microscopy, microcalorimetry, and electron-spin resonance spectroscopy, unique information on the relationship between geometric structure and properties is obtained. The methods can be applied to solve fundamental problems in surface science and to study interesting systems -particularly in the field of catalysis- which would otherwise be difficult (or impossible) to address.

“Catalysis happens at interfaces and experimental techniques are desperately needed to provide information on those systems”, says Freund who is interested in understanding disperse metal and oxide catalysts at the atomic scale. According to the researcher, appropriate samples in this field are very complex so that a combination of techniques is generally required to achieve a complete picture and avoid overestimating individual results. This led him and his colleagues to design new instruments to characterize their systems.

The first method developed by the German team could overcome one of the main disadvantages of scanning probe techniques, namely, their inherent chemical insensitivity, by detecting the fluorescence signal generated by locally exciting the surface with electrons from the tip. The new technique is called photon scanning tunneling microscopy (PSTM) and has been used to study the optical characteristics of metal particles and investigate defect structures in oxide surfaces. Additionally, the researchers are working on a new aberration-corrected instrument for low-energy electron microscopy (LEEM) and photoelectron emission microscopy (PEEM), which will hopefully allow them to investigate single supported nanocatalysts. Freund and co-workers have also built a highly sensitive microcalorimeter that can be used to measure temperature-dependent heats of adsorption on nanoparticle ensembles with aggregate sizes of about a hundred atoms. The fourth technique, called electron-spin resonance (ESR) spectroscopy, can be applied to study particle ensembles and may provide interesting information that is out of reach for other methods, the authors say.

Author: Hans Joachim Freund, Fritz-Haber Institut der Max-Planck Gesellschaft, Berlin (Germany), http://www.fhi-berlin.mpg.de/cp/hjf.epl

Title: Innovative Measurement Techniques in Surface Science

ChemPhysChem 2011, 12, No. 1, Permalink to the article: http://dx.doi.org/10.1002/cphc.201000812

Hans Joachim Freund | Wiley-VCH
Further information:
http://www.fhi-berlin.mpg.de/cp/hjf.epl
http://www.wiley-vch.de

More articles from Life Sciences:

nachricht Zap! Graphene is bad news for bacteria
23.05.2017 | Rice University

nachricht Discovery of an alga's 'dictionary of genes' could lead to advances in biofuels, medicine
23.05.2017 | University of California - Los Angeles

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Scientists propose synestia, a new type of planetary object

23.05.2017 | Physics and Astronomy

Zap! Graphene is bad news for bacteria

23.05.2017 | Life Sciences

Medical gamma-ray camera is now palm-sized

23.05.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>