Question

why pure iron canot used to make parmanet magnets

Answer 1

because soft iron has low retentivity it is not used to make permanent magnets but alnico can be used.

Answer 2

Iron does not maintain magnetism. We you put a soft Iron coil into a coil wire it magnetises but loses it once you take it out (a brief explanation) however we use Steel because it is one of the only pre-unmagnetised metals and it retains magnetism