Issue Date: March 23, 2018
Chemistry in Pictures: Hold it right there
These magnets float in midair thanks to superconductivity. The black disks beneath each magnet are made out of a material called yttrium barium copper oxide (YCBO), which acts as a superconductor when it is cooled down. When a magnet comes close to cold YBCO (cooled in these photos to –196 °C with liquid nitrogen), electrons in YBCO move around and produce magnetic fields strong enough to push back on the magnet and make it levitate. In most regular conductors, a small amount of resistance in the material puts the brakes on those moving electrons so that the magnet can’t “float.” In superconductors, the electrons keep moving until the material warms up above its superconductive temperature—for YBCO, that happens at –180 °C. Professor Ryan Latterman made these YBCO samples in his inorganic chemistry class at Wisconsin Lutheran College by pressing together yttrium(III) oxide, barium carbonate, and copper(II) oxide powders and heating up the mixture.
Submitted by Ryan Latterman
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