Researchers Show Temperature Can Dramatically Affect Behavior of 2-D Materials

A tin selenide monochalcogenide monolayer at room temperature.
Courtesy of Edmund O. Harriss

A tin selenide monochalcogenide monolayer at room temperature.

FAYETTEVILLE, Ark. – New research at the University of Arkansas shows that temperature can be used to dramatically alter the behavior of two-dimensional materials that are being investigated as candidates to power the next generation of electronic devices.

The research revealed black phosphorous and monochalcogenide monolayers act differently than any other known 2-D materials at any given temperature because there are four ways to create their atomistic arrangement, and these four arrangements compete and lead to disorder, said Salvador Barraza-Lopez, an assistant professor of physics at the University of Arkansas.

“Remarkably, nobody had found that some of these two-dimensional materials become disordered at a room temperature and well before they melt,” Barraza-Lopez said. “At the transition temperature the unit cell transforms from a rectangle onto a square and all material properties change.”

An international research team led by Barraza-Lopez and Pradeep Kumar, assistant professor of physics at the U of A, published its findings in Nano Letters, a journal of the American Chemical Society.

The black phosphorous and monochalcogenide monolayers become disordered at a finite temperature, Barraza-Lopez said.

“At that moment, the structure transforms from a rectangle to a square and its behavior also changes,” he said. 

Having access to the Trestles supercomputer at the Arkansas High Performance Computing Center was crucial to the study, Barraza-Lopez said.

Barraza-Lopez and Mehrshad Mehboudi ran multiple calculations on Trestles for about three weeks each and without interruption. Mehboudi is a doctoral student in the university’s interdisciplinary microelectronics-photonics graduate program.

“There is no way we could have achieved these results in the timeframe we did without Trestles,” Barraza-Lopez said.

The work benefited from contributions by Hugh Churchill, assistant professor of physics at the U of A, and Edmund Harriss, a clinical assistant professor in the U of A Department of Mathematical Sciences.

Additional contributors were Arend van der Zande and Wenjuan Zhu of the University of Illinois, Alejandro A. Pacheco-Sanjuan of the Universidad Technica Federico Santa Maria in Chile, and Alex M. Dorio, an undergraduate at Oklahoma State University who participated in a Research for Undergraduates experience at the U of A last summer. 


Salvador Barraza-Lopez, assistant professor
Department of Physics

Chris Branam, research communications writer/editor
University Relations


Spring Break 2018 Is Here

Chancellor Joe Steinmetz and Big Red wish the U of A community a relaxing and safe spring break and look forward to everyone returning to campus March 26 to finish out the year.

New Login System Starting Today

Starting today, UARK Gmail, Blackboard and other services will use a new, secure login system called Azure. Popular services such as Office 365, Box and Kaltura are already using Azure to process logins.

Social and Demographic Factors Linked to Charitable Giving in Recent Study

Characteristics that predict higher levels of giving include age, sex, political affiliation, trust and social connectedness.

UAMS Physical Therapy Students Practice in U of A Nursing Simulation Labs

University of Arkansas for Medical Sciences students in the physical therapy program visited the the Eleanor Mann School of Nursing to run through practice scenarios in simulation labs.

Teacher Education Career Fair

The Teacher Education Career Fair, for all students seeking employment opportunities within the education industry, will be from 3:30-6:30 p.m. April 3, in the Arkansas Union Ballroom.

Newswire Daily