OREGON STATE UNIVERSITY

BASIC MATERIALS ADVANCE COULD AID ELECTRONICS INDUSTRY

07/05/1996

CORVALLIS - Researchers today announced a fundamental advance towards the future use of "colossal magnetoresistance," a concept that holds great potential for improvements in computer memory and the recording industry.

If perfected, this electronic phenomenon could dramatically improve the amount of data or information that can be stored on magnetic tapes, computer disks or other magnetic devices.

Only limited applications are now being made, scientists say, but the latest advance will point the way towards new research directions and types of materials that may be developed with this property.

The discovery was outlined today in the professional journal Science by a collaborative research team from Oregon State University, Dupont, Bell Laboratories, the Lawrence Livermore National Laboratory and the National Institute of Standards and Technology.

"This work describes a new route to creating this type of material that could be important," said Arthur Sleight, an OSU professor of chemistry.

With new approaches, the researchers hope that these materials could eventually be made to operate at room temperature - a key hurdle not now possible, but essential to their widespread commercial application.

Colossal magnetoresistance, Sleight said, is a known phenomena in which materials exposed to a magnetic field undergo a huge, and potentially permanent, increase in their electrical conductivity.

"Magnetic fields can have a minor effect on the electrical conductivity of many materials," said Sleight, who is the Milton Harris Professor of Materials Science at OSU. "With the ones that we describe as having colossal magnetoresistance, the effect is quite dramatic. It's almost like turning a material that used to be an electrical insulator into a conductor."

The value of this characteristic, researchers say, is that electronic devices created with these new materials can more effectively retrieve data from magnetic storage devices, such as audio tape or computer disks. That allows the data on these devices to be far more concentrated.

This characteristic has been recognized in some materials, such as lanthanum manganese oxide, for some time.

But in the Science article, the researchers announced the discovery of a new material - thallium manganese oxide - with the same characteristics. And they described the electronic and atomic behavior of manganese in a way not previously understood and one that challenges the conventional wisdom of how the materials function.

Neither the old, or the new material with colossal magnetoresistance successfully jumps the hurdle of room temperature operation, the scientists said. But the improved understanding of these materials should open some new avenues of research, Sleight said.

There is a high level of interest in these new materials in the computer and electronics industry, Sleight said.