Two members of the ISU faculty have recently been honored for their achievement in research work.

Anson Marston Distinguished Professor Karl Gschneidner and Associate Scientist Vitalij Pecharsky received a 1997 Materials Sciences Award for their development of a new magnetic material that may revolutionize refrigeration techniques.

Gschneidner said it was a honor to be the recipient of the award because program managers across the country chose the Ames Lab project over other excellent research projects entered in the competition from other laboratories.

Magnetic refrigeration technology has been around for over a decade, Gschneider said. It relies on magnetocaloric materials, which heat up when they are magnetized and cool down when they are demagnetized.

Most cooling systems today, from air conditioners to refrigerators, depend primarily on expanding and contracting vapors of chemical liquids. Not only does that take a lot of energy, but chlorofluorocarbons and ammonia could be released into the environment, he said.

In the past, magnetocaloric materials did not have a sufficient temperature range or power to make them a practical substitute for conventional systems, according to the Ames Lab Inquiry publication.

But about eight years ago, Gschneidner said, the Astronautics Corporation of America asked Ames Laboratory, which is a Department of Energy research facility, to work on developing better magnetic cooling materials.

In the past year, using a combination of germanium, silicon and gadolinium, the Ames Lab delivered a new material which not only has a “benign” effect on the environment, but also uses a lot less energy than conventional systems, Gschneidner said.

“This is a tremendous breakthrough,” Gschneidner said in Inquiry magazine. “I think it’s going to put magnetic refrigeration in the market.”

The prototype refrigerator, cooled by Gschneidner’s and Pecharsky’s material and designed by Astronautics, will have a range of approximately -30 F to 63 F, Gschneidner said. That makes it ideal for industrial refrigeration and air conditioning, but the potential for the material does not end there.

Before the development of this material, magnetocaloric materials were composed of gadolinium or gadolinium alloys. The breakthrough came when Gschneidner and Pecharsky added germanium and silicon to gadolinium, Gschneidner said.

By continuing to experiment with the ratio of germanium to silicon, they were able to increase the efficiency of the material and to lower the useful temperature range of operation as far as -405 F, according to Inquiry.

As the material and technology become more refined, they will become useful for smaller appliances, such as air conditioners in automobiles and home refrigerators. In some instances, the conventional technology will be rendered obsolete, Carl Zimm, chief scientist at Astronautics, said in Inquiry.

Gschneidner said he expects the technology to be on the market in the next five to ten years, but he added, “It depends on how much money we get to develop new materials and the technology.”

Not only will magnetic cooling revolutionize the refrigeration industry, it will have a significant impact on the fuel industry as well, according to Inquiry.

Liquid hydrogen has the potential to be an ideal source of fuel. Not only does it burn cleanly, but it is a renewable resource. It is not a practical fuel source today in part because of the energy needed to turn hydrogen from a gas into a liquid, the magazine article said.

The efficiency of magnetic refrigeration and its temperature range will take care of that problem, making liquid hydrogen a viable energy source in the future.