IT HAS BEEN NEARLY A decade since the world was shocked by the discovery of "warm" superconductors--materials that carry current without any resistance at relatively high temperatures. Unfortunately, that breakthrough hasn't yet led to major commercial products, in part because the materials can't carry enough current.
Now, researchers at Los Alamos National Laboratory have broken through a key barrier. At a scientific meeting on Apr. 19, they announced development of a flexible, ribbon-like superconductor that can carry more than 1 million amperes of current per square centimeter of "wire." That's 100 times more than the previous record.
There's nothing unusual about the basic idea: depositing a layer of superconducting ceramic onto an inexpensive nickel-alloy tape. The secret is in between. Before the ceramic is put down, the nickel surface is primed with a layer of cubic zirconia. The extra layer keeps the ceramic crystals aligned, and that ensures higher current
Now, predicts team member Xin Di Wu, superconducting wire will finally find widespread applications, ranging from smaller magnetic resonance imaging (MRI) machines to better motors that can be cooled with inexpensive liquid nitrogen.