One of the researchers' big challenges in making this superconductor magnet was ensuring it stayed intact. Lines of magnetic flux in a superconductor strongly repel each other. The material researchers used to make this superconductor, gadolinium barium copper oxide, is brittle, ceramic-like stuff. Trapping this strong of a magnetic field inside this material could cause it to explode. To strengthen the material, researchers altered its structure at a molecular level. They also "shrink-wrapped" it with a band of stainless steel.