A Cornell University team, pursuing mathematical predictions from five years prior, has produced a ferroelectric thin film from two non-ferroelectric materials. Similar to the University of Pittsburgh's tiny transistor, the film uses strontium titanate, but in a much different manner.

While ferroelectric materials are not uncommon -- you can find them in subway pass cards and the like -- the materials have been limited to memory device applications. Ferroelectrics make perfect flash memory devices as their memory state of on or off can be switch instantly with very little power.

But where this new film, composed of silicon and strontium titanate, may shine is in the realm of transistors. A dream hunted by scientists for more than a decade has been the instant-on transistor, and the Cornell film may put them one step closer.

These theoretical instant-on transistors could revolutionize the way handheld and more permanent computers work. One need not imagine far to grasp the concept of a solid state computer which doesn't need to be booted, but simply powered off or on. Its state remains exactly what it was at power off and acts like nothing has happened in the meantime the next time it's powered on.

Cornell achieved this new material through a process called molecular-beam epitaxy, described as "atomic spray painting." The strontium titanate, which is normally non-ferroelectric, was grown onto a silicon substrate using the epitaxy process. In doing so, the strontium titanate was squeezed to fit within the spaces of the silicon molecules. This constriction of the molecules caused the strontium titanate to become ferroelectric.

"Changing the spacing between atoms by about 1.7 percent drastically alters the properties of strontium titanate and turns it into a material with useful memory properties," explained professor Long-Qing Chen of Pennsylvania State University.

"The technological implications are staggering," said Professor Jeremy Levy of the University of Pittsburgh, whose team created the tiny transistor. His research team made the measurements of the Cornell film to prove its ferroelectric properties.

A paper on the Cornell ferroelectric film has been published in the April 17 edition of Science and is authored by postdoctoral associate Maitri P. Warusawithana.