Magneto-optical characterization of the ferromagnetic domains in vanadium iodine. Image: Ames Laboratory, US Department of Energy.
Magneto-optical characterization of the ferromagnetic domains in vanadium iodine. Image: Ames Laboratory, US Department of Energy.

Scientists at the US Department of Energy's Ames Laboratory, Brookhaven National Laboratory and Princeton University have discovered a new layered ferromagnetic semiconductor, a rare type of material that holds great promise for next-generation electronic technologies.

As their name implies, semiconductors are the Goldilocks of electrically conductive materials – not a metal and not an insulator, but a ‘just-right’ in-between whose conducting properties can be altered and customized in ways that create the basis for the world's modern electronic capabilities. Especially rare are semiconductors that are closer to an insulator than a metal.

The recent discovery of ferromagnetism in semiconducting materials has been limited to a handful of mostly chromium-based compounds. But in this study, reported in a paper in Advanced Materials, the researchers discovered ferromagnetism in a vanadium-iodine (VI3) semiconductor, a material that has long been known, but ignored.

Scientist Tai Kong said it was like finding a "hidden treasure in our own backyard". Now a postdoctoral researcher in the lab of Robert Cava, a professor of chemistry at Princeton University, Kong completed his PhD research at Ames Laboratory under the supervision of Paul Canfield. When Kong found that this new material could have ferromagnetic properties, he turned to Ames Laboratory for the magneto-optical visualization of magnetic domains that serves as the definitive proof of ferromagnetism.

"Being able to exfoliate these materials down into 2D layers gives us new opportunities to find unusual properties that are potentially useful to electronic technology advances," said Kong. "It's sort of like getting a new shape of Lego bricks. The more unique pieces you have, the cooler the stuff you can build."

The advantage of a semiconductor with ferromagnetism is that its electronic properties become spin dependent, with the electrons aligning their spins along the internal magnetization.

"This creates an additional control knob to manipulate currents flowing through a semiconductor by manipulating magnetization, either by changing the magnetic field or by other more complex means, while the amount of current that can be carried may be controlled by doping [adding a small amount of other materials]," explained Ruslan Prozorov, a laboratory scientist at Ames. "These additional ways to control behavior and the potential to discover novel effects are the reason for such high interest in finding insulators and semiconductors that are also ferromagnets."

This story is adapted from material from Ames Laboratory, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.