I needed a refresher on superconductors and superconductivity.
Superconductivity was discovered on April 8, 1911 by Heike Kamerlingh Onnes, who was studying the resistance of solid mercury at cryogenic temperatures using the recently produced liquid helium as a refrigerant. At the temperature of 4.2 K, he observed that the resistance abruptly disappeared.
Okay, but what the heck does that mean? Maybe a video would help.
This three minute video was quite effective in demonstrating how ceramics and other “superconducting” materials can float over a magnetic field at extremely low temperatures.
What types of materials make good super conductors?
Superconductor material classes include chemical elements (e.g. mercury or lead), alloys, ceramics, and organic superconductors.
Some materials have higher magnetic fields than others.
Type I superconductors were discovered first and require the coldest temperatures to become super conductive. For example lead becomes super conductive at temperatures below 7.196 K (Kelvin).
To put that temperature in perspective, on the Kelvin scale the freezing temperature for water is 273.16 K.
Type II superconductors work at warmer temperatures. The warmest Type II superconductor is Hydrogen Sulphide at a balmy 203 K (-73 C°).
So now I think I’m ready to dive into @Chris ‘s articles on room temperature super conductors. Should be interesting.
Humorous aside. Please don’t confuse superconductivity with the “diving bell phenomenon” video that I shared with @dkeller .