Physicists Find Structural Phase Transitions in 2-D Atomic Materials
FAYETTEVILLE, Ark. – An international team led by University of Arkansas physicists has discovered drastic changes in material properties occurring in a group of two-dimensional materials that are being investigated as candidates to power the next generation of opto-electronic devices.
The findings, published in the journal Physical Review Letters, reveal the rich properties of a new class of “phase-change” 2-D materials known as group-IV monochalcogenide monolayers and bilayers.
The U of A team consisted of Mehrshad Mehboudi, a doctoral student; Yurong Yang, a research assistant professor; Laurent Bellaiche, Distinguished Professor of physics; and assistant professors of physics Pradeep Kumar and Salvador Barraza-Lopez. Their collaborators were Benjamin Fregoso at the University of California-Berkeley, Wenjuan Zhu and Arend van der Zande, both at the University of Illinois; and Jaime Ferrer from Universidad de Oviedo in Spain.
“We are the first team to even realize the possibility of such two-dimensional structural transitions in 2-D atomic materials, and the first team to ever study the effect of such transitions on material properties,” Barraza-Lopez said.
The transition is the change from a rectangle to a square unit cell occurring near room temperature. As a result of the transition, optical properties, charge transport, and intrinsic dipole moments in the case of monolayers are shown to change in an abrupt manner.
“These changes in properties make these materials an exciting platform for novel optoelectronic applications, and they also uncover fundamental physics of structural phase transitions in reduced dimensions,” Barraza-Lopez said. “No such detailed analysis had been provided before this work.”
The research was carried out entirely on the Trestles supercomputer in the Arkansas High Performance Computing Center at the U of A.
Salvador Barraza-Lopez, assistant professor
Department of Physics
Schulte will offer a preview of Honors College Signature Seminar coming next spring during a lecture at 5:15 p.m. Wednesday, Sept. 20, in Gearhart Hall Auditorium.
Three students in the graduate athletic training program — Eric Schwartz, Kristen Peterson and Mariellen Veach — won scholarships and research grants from the Southwest Athletic Trainers' Association.
Bob Maranto, a professor in the Department of Education Reform, argues in a Chronicle of Higher Education article that worries of university students being swayed to liberal viewpoints is overblown.
The Arkansas Teacher Corps works to recruit, train and support individuals from all majors and backgrounds to serve as outstanding teachers for Arkansas students.
Weiyi Ma and Amanda Williams have joined the faculty in the U of A's School of Human Environmental Science's human development and family sciences program.