I was only guessing. Jeff Driscoll found the answer in these videos
http://www.youtube.com/watch?v=VyOtIsnG71U <http://www.youtube.com/watch?v=VyOtIsnG71U&feature=related> &feature=related http://www.youtube.com/watch?v=6lmtbLu5nxw <http://www.youtube.com/watch?v=6lmtbLu5nxw&feature=related> &feature=related It looks like they took a thin sapphire disk of the sputtered Y123, added a disk of solid nitrogen on top and wrapped it in a clear film – which then fogs up to make it appear to be cloth. Very clever … but the real science is in the crystal alignment and doping of the thin films. Jones From: Jed Rothwell I thought it was solid nitrogen. I thought the person asking questions referred to it as "liquid nitrogen" out of force of habit, but he meant "solid." I have seen solids which were referred to as nitrogen, looking like dry ice (solid CO2). Wikipedia sez: "Liquid nitrogen can easily be converted to the solid by placing it in a vacuum chamber pumped by a rotary vacuum pump. Liquid nitrogen freezes at 63 K (−210 °C; −346 °F)." - Jed
