Science Buddies: "Ask an Expert"

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Hi, I'm thinking of doing the project linked above, but I am wondering about the type of magnets it calls for: "5–10 permanent iron magnets of equal size and strength." I visited a hobby store today and asked about "permanent iron magnets," and the clerk wasn't sure what I was referring to. They carried ceramic magnets or very small rare earth magnets. Searching online, I can't find anything to purchase that is specifically called a "permanent iron magnet." My question is, would it be alright to use ceramic magnets for this experiment, or what would you recommend?

Thanks in advance for your help!

Hi tattarrattat,

This is a great experiment. It's one I attempted to do when I was a kid. Due to lack of guidance, I never completed it, but with our help here on Science Buddies, I know you can do it.

"Permanent iron magnets" used to be the only kind of magnets a person could get. We used to buy them at the hardware store. They were pieces of iron, or high iron content steel, that were magnetized. So perhaps this project was written up a long time ago.

What this experiment is attempting is to do is answer the question "Are some magnetic materials more temperature-dependent than others?" So, actually, it would be best to test magnets made of more than one material. The shape and size of the magnet will also be important because of the way you are instructed to test magnet strength in this experiment. So if you want to determine if different magnet materials work differently at different temperatures, they should all be the same size and shape as well.

So, yes, you can use modern ceramic or rare earth magnets for this experiment. You might even be able to find some older AlNiCo magnets - the technology that came right before rare earth.

Go ahead and have a great time with this experiment.

Thank you for your help, Ed Neu!