Pure iron can have two different crystal structures as its temperature is increased from room temperature to its melting point. At room temperature it is body-centered cubic, between 912 and 1394 C if ...

1927), that quenched carbon steels contain a phase with a tetragonal crystal structure, which might be considered as a deformation of the body-centred cubic structure of α-iron. This has been ...

first performed X-ray diffraction measurements at high pressure and high temperature corresponding to the condition at the center of the Earth and determined the crystal structure of iron in Earth ...

In fact, the only thing needed to make them is iron and nitrogen, plus an understanding of crystal structure and some engineering ingenuity. To start things off, what even is a permanent magnet?