It‘s for science. Please help!
steel is a hard magnetic material and hence when it is magnetised once it will conserve its magnetism for a relatively long period of time. That is why it is used to make permanent bar magnets. On the other hand iron is a soft magnetic material and hence once magnetised it will lose its magnetism rather instantaneously.That is why it is used in the core of transformers and in electromagnets.
I will use Iron as steel have some impurities in the form of alloys and it could decrease power of magnet. Good luck
