News

September 2000

News about Science, Technology and Engineering from Iowa State University

"Cool" materials turn into hot research
A group of materials that exhibit an enhanced ability to cool down and heat up in response to changes in magnetic fields -- a property discovered at the U.S. Department of Energy's Ames Laboratory at Iowa State University -- could have uses that extend far beyond temperature regulation. The materials, already being studied for magnetic-refrigeration technology, have possible uses in energy-conversion devices and in sensors to detect changes in magnetic field, temperature and pressure.

Now, a four-year Ames Lab project will provide a better fundamental understanding of why the materials respond so dramatically to changes in temperature and magnetic field. Scientists will explore the properties of gadolinium-silicon-germanium and several closely related materials. The alloys possess an unusual combination of three properties -- a giant magnetocaloric effect, giant magnetoresistance and colossal magnetostriction. Because of these properties, a relatively small change in the magnetic field surrounding the materials produces a tremendous change in their temperature, dimensions and electrical resistance.

"Some materials may possess one or two of these properties, but what's unique about this material is that all three changes take place in the same alloy and all three changes are quite large -- among the largest ever seen," said senior metallurgist Karl Gschneidner, who will direct the research project. For more information, contact Gschneidner, (515) 294-7931, or Susan Dieterle, Ames Lab Public Affairs, (515) 294-1405.

Simple steps can make your computer more secure
Recent instances of hackers breaking into corporate and government computer systems should be a sign to all computer users to guard against attacks on their machines, according to Jim Davis and Doug Jacobson, both ISU associate professors of electrical and computer engineering. Davis and Jacobson teach ISU students how to identify and thwart cyber attacks, and are co-directors of ISU's Information Systems Security Laboratory, a National Security Agency Center of Excellence.

There are more than just common viruses, like "Melissa" or the "Love Bug," floating around on the Internet these days. There also are "Trojan Horses" and "buffer overflows" and "denial of service" attacks that can bring a company's, or your, computer system to its knees. But there are steps to make your computer more robust in today's world of computer interconnectivity, Davis and Jacobson said.

Use a secure password. A good password is six to eight characters in length, comprising letters and numbers and is not a word in the dictionary nor should it be connected to information others know about you, like your phone number or birth date.
The value of backing up. Backing up all of your important programs and data will save you time and money should your system be attacked, Jacobson said.
Hold the Java and the cookies. Disable Java and JavaScript in your web browser unless you absolutely need it to access a web site. Also have your computer warn you before accepting "cookies."
Scanners and firewalls. Get a good virus scanner, which checks all of the files on a computer to see if there are viruses, and be careful of what you download and run on your computer. Personal firewall software will help protect you when you are on the Internet.
Exercise common sense. Take time to read and understand the privacy policies of any web site you give information to. Many sites collect and disseminate information. A reputable site will publish their privacy policies.

"Simple preventative tasks early on can save you time, money and a considerable amount of hassle later on," Davis said. For more information contact Davis, (515) 294-0659; Jacobson, (515) 294-8307; or Skip Derra, ISU News Service, (515) 294-4917.

Lab will focus on boosting computer data storage
Imagine sitting down to a personal computer that stores 10 to 50 times more information than today's top models, doesn't lose data during power interruptions and starts immediately without needing the traditional "boot-up" process. Advances such as these are being explored in the rapidly growing field of magnetoelectronics, which combines microelectronics and magnetics to create new technologies that will quench the public's growing thirst for greater data-storage capacities on computers.

Scientists at the U.S. Department of Energy's Ames Laboratory and Iowa State University will become part of those research efforts, thanks to a $530,000 grant from the Roy J. Carver Charitable Trust, Muscatine, Iowa, to establish a magnetoelectronics laboratory. Much of the work in the new lab will involve using an ion-beam deposition system to produce materials in the form of thin films for technologies that will expand computer data-storage capacities. David Jiles, a researcher affiliated with both Ames Laboratory and ISU, is heading up the project and anticipates having the facility ready in about six months.

"Magnetoelectronics is a very, very hot area," Jiles said. "We've all got computers and we all want to be able to store more and more data on them. Ames Laboratory and Iowa State need to get into this area because there's a huge market for this type of cutting-edge technology." For more information, contact Jiles, (515) 294-9685, or Susan Dieterle, Ames Lab Public Affairs, (515) 294-1405.

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