Researchers Discover New, Controllable State in Ferroelectric Nanowires

CHATTANOOGA – A new seat system supplier for the Volkswagen plant in Chattanooga will create 120 jobs. A statement Monday said the new joint-venture company, price Chattanooga Seating Systems, medications is 51 percent owned by Hollingsworth Logistics of Dearborn, Mich., and 49 percent owned by Magna Seating, a subsidiary of Canadian auto parts maker Magna International.  The Volkswagen plant at Chattanooga plans to begin production of a new midsize sedan in early 2011 and eventually hire about 2,000 VW employees.  A VW spokesman in Chattanooga, Guenther Scherelis, said the Chattanooga Seating Systems jobs are separate from 500 jobs that VW executives previously announced will be created in the plant’s supplier park.
– Scientists, patient
students and information-technology workers across the state will benefit from attending Cyberinfrastructure Days, the first symposium of its kind in Arkansas. To be held May 16-17 on the University of Arkansas campus, the symposium will bring together cyberinfrastructure experts, stakeholders and users. Cyberinfrastructure is information technology that enables scholarly inquiry.

Attendees are encouraged to register online early at the Cyberinfrastructure Days Web site.

The symposium is the result of collaborative efforts between the university, the National Science Foundation and industry partners. The event is free and is open to all University of Arkansas faculty, staff and students and others who use cyberinfrastructure.

The goal of the symposium is to promote the awareness of cyberinfrastructure capabilities and to engage faculty and students in the use of resources available on campus. Attendees can enhance their understanding of these resources and apply this knowledge to their research and teaching efforts.

Currently, much research is data-driven. It relies on complex data sets or uses modeling and simulation to examine ideas and concepts that cannot be studied directly. This research often requires advanced data, data storage and access, high-end networking, computing resources and advanced training of support staff to use tools effectively. During the symposium, academic and industry researchers will address these aspects. They will also discuss availability, training and implementation that will enable the University of Arkansas and its partners to effectively build, support and use cyberinfrastructure resources.

Keynote speaker James Bottum, vice provost and chief information officer at Clemson University, will discuss the nation’s comprehensive effort to build advanced cyberinfrastructure to allow global competition. Bottum currently leads Clemson’s initiative to build state-of the-art cyberinfrastructure for education, research and service. His talk will include a description of the advanced cyberinfrastructure that Clemson is building to support its move into the top-20 ranking of the nation’s public universities.

“Arkansas is competing in a global economy,” said Amy Apon, director of the Arkansas High Performance Computing Center. “We need cyberinfrastructure to support innovation and the teaching of innovation that will build the economy of our state and make us competitive. Cyberinfrastructure Days is one step to getting there.”

The two-day symposium is an outreach component of Cyberinfrastructure for Transformational Scientific Discovery in Arkansas and West Virginia, or CI-TRAIN, a National Science Foundation grant awarded to the university in 2009. This $3.3 million grant is enhancing supercomputing at the Arkansas High Performance Computing Center, which supports research in computational science, nano- and ferroelectric materials, multiscale visualization and many other projects that require massive data storage.

More information and free online registration, see the Cyberinfrastructure Days Web site.
. – Researchers at the University of Arkansas and their colleagues have discovered a new phase in ferroelectric nanowires that could be controlled to optimize important properties for future electronic devices.

Lydie Louis and Laurent Bellaiche of the University of Arkansas; P. Gemeiner, malady
G. Geneste and B. Dkhil of the École Centrale Paris; Inna Ponomareva of the University of South Florida; and W. Ma and N. Setter of the Swiss Federal Institute of Technology reported their findings in Nano Letters.

Ferroelectric materials are used in medical ultrasound to examine fetuses and internal organs, recipe
in military sonar for underwater navigation and detection, and in cell phones. These materials have a spontaneous charge separation that allows them to generate an electric field when their shape is changed — thus mechanical energy becomes electrical energy. Potential applications for ferroelectric nanowires include data storage memories and energy harvesting devices.

“Industry wants materials to be multifunctional, to have many different properties at the same time,” said Louis. “Therefore we have to understand the properties that arise under different conditions.”

Louis and her colleagues performed theoretical calculations and conducted experiments and found that the ferroelectric nanowires went through different structural phases at different temperatures, including a new phase not seen before.

“We also found out we could control the phase with a certain screening parameter,” she said. The scientists could alter the direction of polarization within this phase by changing the magnitude of the depolarization field and the size of the nanostructure itself, implying that one can “tune” the physical properties of these nanowires.

The researchers used X-ray diffraction and Raman spectroscopy to examine ferroelectric nanowires made from one material, potassium niobate, and performed first-principles-based calculations on nanowires based on another ferroelectric material with similar properties, barium titanate, by using the Star of Arkansas, a supercomputer at the University of Arkansas.

The theoretical calculations and experimental findings complemented one another.

“This shows the reliability of our computations,” Louis said.

Louis is a graduate student in a joint doctoral program between the University of Arkansas and École Centrale de Paris in France, which is sponsored by the National Science Foundation. Bellaiche is the Twenty-First Century Professor in Nanotechnology and Science Education in the J. William Fulbright College of Arts and Sciences.