By adding tungsten to vanadium oxide, Texas A&M researchers found they could better control, or tune, the material’s transition to and from conductor to insulator — properties that could be exploited in powering future computers. (Erick J. Braham)
In the paper, the team describes doing just that by adding tungsten to the material. Among other things, they showed that tungsten allows the transition to occur over two very different pathways. The result is that the transition from insulator to conductor happens easily and quickly, while the transition from conductor back to insulator is more difficult.
“Think of it as driving from point A to point B and back again,” Banerjee said. “Going there, you take a superhighway, but coming back, you’re on back roads.”
Essentially the addition of tungsten allows the vanadium oxide to switch quickly in one direction and much more slowly in the other — phenomena that could be exploited in future computers.
“It provides an additional ‘knob’ to tune how you go back and forth between the two states,” said Erick J. Braham, a Texas A&M chemistry graduate student and member of the Banerjee Laboratory who was first author on the paper.
The team has also found that the addition of tungsten allows them to better control, or tune, the different temperatures where the transitions occur.
Banerjee notes the interdisciplinary nature of the work, which involved four groups with expertise ranging from computational materials science to electron microscopy, has been key.
“We’ve really looked at this puzzle from different ends to try to make sense of exactly what’s going on,” he said. “It’s been very exciting.”
Additional authors from Texas A&M are Dr. Raymundo Arróyave from materials science and engineering; Nathan A. Fleer, graduate student in chemistry and materials science and engineering; Diane Sellers, assistant research scientist in chemistry and materials science and engineering; Ruben Villarreal, graduate student in materials science and engineering; and Katie E. Farley and Emily Emmons, both former graduate students. Authors from the University of Illinois at Chicago are Dr. Reza Shahbazian-Yassar, professor, and Hasti Asayesh-Ardakani, a visiting researcher. Their work was supported by the National Science Foundation and the Air Force Office of Scientific Research.
This story by Elizabeth Thomson originally appeared on the College of Science website.