A team of scientists has for the first time used a new technique to measure changes in ultrathin materials, which could eventually help develop faster, higher-capacity, more stable electronic memory.

Using a technique known as ultraviolet Raman spectroscopy, the international group was able to measure precise conditions under which so-called "ferroelectric" materials as little as one molecule thick change their state.

Leading experts in the field previously thought it impossible to make such measurements.

The research appears in the journal Science.

The scientists found ways in which a layer of barium titanate could store a switchable electric field at a range of temperatures, configurations and thicknesses, including one as thin as four-tenths of a nanometre or 400 millionths of a centimetre.

"There are many techniques for measurement at a larger scale," team leader Xiaoxing Xi, a professor of physics and material sciences at Penn State University in University Park, Penn., about 220 kilometres east of Pittsburgh, told CBC.ca.

However, when it comes to measuring changes in electromagnetic properties of materials at the so-called "nanoscale," those techniques fall short for precisely and accurately detecting those changes, Xi said.

"The key point is to detect the transitions in the nanoscale system. It is very difficult," Xi said. "Other techniques have not been able to do that."

Faster, more stable memory

The scientific understanding of how such nanoscale materials behave under different conditions that the new technique provides could eventually help researchers make faster, higher-capacity and more stable electronic memory, for use in such things as computers or so-called "smart cards."

"The advantage of using ferroelectric materials is to make nonvolatile memory," Xi said.

In other words, once data is written to memory, it does not need power to continue to store that data.

The further development of such memory could lead to the creation of computers that instantly turn on and off without having to wait for software to load or save data.

"Common semiconductors cannot do it," Xi said, referring to the silicon-based memory used in modern computers for RAM, or Random Access Memory.

"FRAM, or Ferroelectric RAM, is one of the two most promising technologies," he said, adding that the other candidate — MRAM, or Magnetic RAM — has problems that make it less ideal.

"The work led by Xiaoxing Xi on nano-thick ferroelectric multilayers is groundbreaking," Refik Kortan, a program manager at the Basic Energy Sciences division of the U.S. Department of Energy, said in a statement. The federal agency helped sponsor the study along with the U.S. National Science Foundation, the Office of Naval Research, and NASA.
 
Ultraviolet Raman spectroscopy is a new technology — less than 10 years old — that is in the early stages of being developed, Xi said.

The research team included 22 scientists at Penn State, the universities of Puerto Rico, Wisconsin and Michigan, Rutgers University in New Jersey, the University of Valencia in Spain, as well as the Los Alamos National Laboratory in New Mexico and the National Atomic Energy Commission in Argentina.