Nav: Home

New electron source for materials analysis

March 15, 2017

How can solar cells be made more efficient? How can solar and wind energy be best stored for later use? Technologies for the transformation of the German energy sector (Energiewende) require tailor-made materials which are both affordable and efficient. One important tool in the search for such materials is high-resolution electron energy loss spectroscopy, HREELS for short. This method entails bombarding the material to be investigated with a beam of electrons. The electrons are deflected from the surface of the material and in doing so lose some of their energy. This loss of energy can be measured, thus permitting conclusions to be drawn about the properties of the material, such as its ability to conduct electricity or heat.

HREELS measurements can, however, be very time-consuming. "The really interesting part of the electrons' energy loss is angle-dependent," explains Dr. François Bocquet from Jülich's Peter Grünberg Institute. "This is why it must be measured from different directions. So far, it was only possible to measure the energy loss for one angle at a time. Measurements of a single sample thus took a whole day, and sometimes even longer."

Now, François Bocquet and his colleagues have developed a method for measuring a sample within just minutes. Two additional components in their HREELS instrument simplify the measurements: "The first is a hemispherical electron analyser, which has been successfully used in angle-resolved photoelectron spectroscopy for ten years," says Bocquet. "The second is a modified electron source adapted to the electron analyser, which was developed here at the institute." This is optimized by means of specially developed software which ensures that the electrons in the beam have the desired kinetic energy and can be focused on a very small area of the sample. In this way, the analyser can be used optimally - permitting the simultaneous measurement of energy losses from different angles.

"These innovations enable us to investigate samples which are too unstable or sensitive for the previous methods," explains François Bocquet, whose research is also funded by the Helmholtz Association's Initiative and Networking Fund. The scientists usually work under vacuum conditions so that the surfaces to be investigated are not contaminated. "Since, however, no vacuum is ever perfect, we would have to stop the measurements after a few hours and prepare the sample again. Thanks to the new method, this is now no longer necessary," says a delighted Bocquet.

Dr. François C. Bocquet
Peter Grünberg Institute
Functional Nanostructures at Surfaces (PGI-3)
Tel: +49 2461 61-3987

Press contact:

Dr. Regine Panknin
Corporate Communications
Tel: +49 2461 61-9054

Forschungszentrum Juelich

Related Electrons Articles:

Deceleration of runaway electrons paves the way for fusion power
Fusion power has the potential to provide clean and safe energy that is free from carbon dioxide emissions.
Shining light on low-energy electrons
The classic method for studying how electrons interact with matter is by analyzing their scattering through thin layers of a known substance.
Ultrafast nanophotonics: Turmoil in sluggish electrons' existence
An international team of physicists has monitored the scattering behavior of electrons in a non-conducting material in real-time.
NASA mission uncovers a dance of electrons in space
NASA's MMS mission studies how electrons spiral and dive around the planet in a complex dance dictated by the magnetic and electric fields, and a new study revealed a bizarre new type of motion exhibited by these electrons.
'Hot' electrons don't mind the gap
Rice University scientists discover that 'hot' electrons can create a photovoltage about a thousand times larger than ordinary temperature differences in nanoscale gaps in gold wires.
Electrons used to control ultrashort laser pulses
We may soon get better insight into the microcosm and the world of electrons.
Supercool electrons
Study of electron movement on helium may impact the future of quantum computing.
Two electrons go on a quantum walk and end up in a qudit
There is a variety of physical systems that can be used to implement a separate quantum bit, but significantly less research has been done into systems of several qubits or qudits.
Radiation that knocks electrons out and down, one after another
Researchers at Japan's Tohoku University are investigating novel ways by which electrons are knocked out of matter.
Controlling electrons in time and space
A new method has been developed to control electrons being emitted from metal tips.

Related Electrons Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".