Growth of Superconducting Bulk Single Crystals and their use in Leviation Demonstrations

We present our work on the growth of bulk single-crystal YBa$_2$Cu$_3$O$_7$ and a novel superconducting demonstration using our superconductors. We report the first successful fabrication at the undergraduate level of YBa$_2$Cu$_3$O$_7$ superconducting pucks with enhanced flux-pinning properties. We follow a bulk superconductor growth recipe developed by Dr. Kazumasa Iida at the Institute for Metallic Materials in Dresden, Germany. In order to grow a puck that is largely single crystalline in phase, it is necessary to mix portions of both superconducting (YBa$_2$Cu$_3$O$_7$) and non-superconducting (Y$_2$BaCuO$_5$) phases together and fire them at near liquefying temperatures. This process is known as melt-textured growth. We have also constructed a figure-8 track of strong permanent NdFeB magnets to demonstrate the dramatic effect of flux-pinning. This track is outfitted with an accelerator to keep the puck circling the track. We accelerate the puck to a speed that, without the introduction of enhanced flux-pinning, would cause the puck to be thrown from the track. We will show a video of our puck and novel demonstration.