
RESEARCHERS STUDY SUPERCONDUCTIVITY, MAGNETISM IN NOVEL MATERIAL
Date: Thursday, March 01, 2007 @ 23:01:04 UTC Topic: Science
A University of Arkansas physics professor and his colleagues have
created a nanoscale structure that contains both magnetic and
superconducting properties at the same time, and they will be exploring
the properties of this novel material this summer in Switzerland.
Jacques Chakhalian and his colleagues at the Max Planck Institute in
Germany and the University of Grenoble and the National Center for
Scientific Research, both in France, have been awarded research time
and financial support over the next two years at Swiss Light Source at
the Paul Scherrer Institut – the most advanced synchrotron light source
in the world. In 2006, they published a paper in Nature Physics
documenting novel properties at the interface between a superconductor,
known as YBCO, and a ferromagnet, known as LCMO. Their results showed
an interplay between ferromagnetism and superconductivity that had
never been documented before.
“Typically, ferromagnetism destroys superconductivity,” Chakhalian
said. The group’s technique, which allows scientists to combine these
two properties in one thin-film superlattice, opens up a new area of
physics and paves the way for discovering more materials with novel
properties.
To create the lattice, the researchers take a powdered pallet of
the material and use a powerful ultraviolet laser to vaporize the
crystals and deposit them as a multilayer, ultra-thin film on a
substrate. This way they can create one atomic layer at a time.
“You can make it as thin as you want,” Chakhalian said. To find out
more about the unique properties of the superconductor/ferromagnet
material, the research group wants to look at the interface between the
two materials. They plan to do this using the synchrotron at Swiss
Light Source.
The synchrotron light is electromagnetic radiation of varying
wavelengths that can be tuned to a specific wavelength for a particular
experiment. The spectrum at Swiss Light Source varies from infrared
light to soft and hard X-rays. Unlike conventional X-rays, which
diffuse through space, the synchrotron light beams are sharply focused
like a laser beam. This will allow Chakhalian and his colleagues to
study the magnetic and superconducting properties at the interface of
this nanoscale material.
“The main technical challenge is to focus the beam of low energy
photons into a spot the size of a few hundred microns,” Chakhalian
said. Only a few facilities in the world, like Swiss Light Source, have
the technology to create the “soft” X-rays necessary to analyze the
electronic properties of the superconductors and ferromagnets.
The team will conduct their experiment at Swiss Light Source
starting June 18. They will have seven days to complete the first phase
of the research. The award will allow them to return to use the
synchrotron again more than once over the next two years. In the
meantime, they will be busy working with the results of their first
experiments. This project provides a perfect training ground for
University of Arkansas graduate students who are interested in
nanoscience and nanotechnology
“It takes a lot of intellectual effort to analyze the data,” Chakhalian said.
Chakhalian is an assistant professor of physics in the J. William
Fulbright College of Arts and Sciences. In addition to working at the
Swiss Light Source, he also works at the Advanced Photon Source,
Argonne National Laboratories and the ANKA Synchrotron Light Source in
Germany.
Source: University of Arkansas, Fayetteville Via: http://www.physorg.com/news91974487.html
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