|Photograph courtesy of Satoshi Tanda, reprinted by permission from Nature 417:397 copyright 2002 macmillan publishers.|
Crystals are supposed to be hard-edged and well-orderedthink diamondbut Japanese researchers have amazed their colleagues by growing crystals shaped like a ring, a figure eight (right), or a Möbius strip. Satoshi Tanda and his fellow physicists at Hokkaido University and NTT Basic Research Laboratories in Japan crafted these oddities by placing powdered niobium and selenium in a chamber heated to 1,365 degrees Fahrenheit, hot enough to evaporate the selenium. Pressure variations in the chamber caused the selenium to cycle between liquid and vapor. Under those conditions, the two metals combine into whiskerlike crystals that attach to the surface of short-lived selenium droplets. Surface tension causes the whiskers to bend and twist as they grow across a droplet. By the time those niobium-selenium whiskers completely encircle a droplet, they are so contorted that they form the exotic bent shapes. Tanda thinks these twisted atoms could be used to fabricate tiny electromagnetic switches or microscopic batteries.