# Superconductor Question

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1. Nov 17, 2015

### Trevor Stanfill

Hello, I have been looking at superconductors lately and was wondering if there was anywhere I could get a small superconductor online. I realize for it to actually conduct it must be incredibly cold, but I was wondering where I could get a metal that allows for superconduction.

2. Nov 17, 2015

### Pulzz

You can easily buy lead from anywhere. It is a superconductor below 7.25 K

3. Nov 17, 2015

### Staff: Mentor

Have a look here. The German version of it suggests $YBa_2Cu_3O_{7-δ}$. The material depends on the cooling you can achieve.

4. Nov 18, 2015

### f95toli

You can buy demo kits meant for e.g. schools that contain pieces of YBCO. This will become superconducting at 92K, meaning you can use liquid nitrogen (which is easy to get hold of) to cool it.
CAN superconductors.sells kits like this.

if you just want a material that CAN become superconducting then you can pick up just about any metal (with a number of notable exceptions, .e. g gold): aluminium,.lead, titanium, niobium, rhenium etc are some examples.
Aluminum and niobium (as well as a number of Nb compounds) are the most used superconductors in research.

5. Nov 18, 2015

### Trevor Stanfill

Thanks everybody, I think I will go with lead sheets. I plan on building a model maglev for a science project.

6. Nov 19, 2015

### f95toli

You would need liquid helium to cool lead below Tc, not very practical. If you have access to liquid nitrogen you could use YBCO or BSCCO from one of the abovementioned kits to build a train. This is how it is usually done.

7. Nov 19, 2015

### Staff: Mentor

Isn't it far too dangerous to give liquid nitrogen at kids' hands?

8. Nov 19, 2015

### f95toli

Liquid nitrogen isn't particularly dangerous as long as you don't do anything stupid (i.e. drink it or pour it into a sealed container). It is obviously not toxic (but you should never use it in small badly ventilated spaces, e.g. elevators) and getting some on your skin won't hurt you at all as long as it doesn't get trapped in or underneath something (e.g. tight clothes, underneath jewelry). When doing experiments like this I would suggest wearing a T-shirt (again, getting droplets on your skin won't hurt you at all) or loose fitting garments.
Do be very careful if wearing gloves, there are many situations where they are appropriate (if you e.g. might need to touch a metal surface that has been cooled down by the nitrogen), but there is always the risk of getting nitrogen inside the glove (which would be bad).

It is certainly less dangerous to handle than for example boiling water. In fact, "treat it as boiling water" is exactly what I tell students when I teach them how to handle nitrogen.

That said, anyone using it for the first time should be obviously be supervised; and I wouldn't give it to a bunch of small kids. However, it anyone older than say 15 should be fine as long as they are properly supervised.

(I have been using liquid nitrogen/helium on daily basis for 16 years, and I also used to supervise lab exercises in cryogenics and superconductivity back when I was a PhD student; including demos using a Meissner kit)

9. Nov 19, 2015

### ZapperZ

Staff Emeritus
Does your teacher or whoever is supervising this know of your plan?

As has been mentioned, you will need liquid helium to get lead into a superconducting state. Unless you have the money (LHe is not cheap, and it is also in short supply) and the equipment to handle it, it is not a practical solution. Besides, to get a stable levitation, you will need a better Type II superconductor that allows for field-lines penetration.

Again, look for kits that are available for most school laboratory supplies. The YBCO or BSCCO superconductor will only require liquid nitrogen, which is easier to handle and cheaper. And please, PLEASE consult your teacher on the safe handling of any cryogenic fluids. If you look at videos from JLab's "Frostbite theater", they ALWAYS wear proper protective gear such as eye protection when handling such things.

Zz.