Next Generation

Sometimes chance leads to discoveries. Developed last year by Chicago and Argonne National Laboratory researchers, silver chalcogenide sensors (pictured below) can measure magnetic fields up to 600,000 Gauss strong, or more than 1 million times the Earth's magnetic field. The team originally was studying the effect of electrical charges on silver selenide, says research leader Thomas Rosenbaum, the James Franck professor of physics. When below-room-temperature tests produced "strange" results, the researchers applied a magnetic field to the selenide compound in an attempt to understand the phenomenon. Instead they discovered the material's unexpected sensitivity to magnetic fields. Rosenbaum calls it "a classic case of serendipity."

The exceptionally accurate sensors-each measuring 1 cubic millimeter and costing a few cents to produce-can be used in medical exams, such as magnetic resonance imaging, and in computing technology, such as high-temperature superconductors.

Photo by Jason Smith