Layered polycrystalline structure and method of making the same

A layered polycrystalline structure comprising:

• a seed crystal layer containing Cr element at a concentration level equal to or larger than 50 at %;
• a Co-based alloy magnetic crystal layer containing Cr element diffused along a grain boundary, said Co-based alloy magnetic crystal layer including a lower part partly excluding Cr element out of a lattice of the Co-based alloy magnetic crystal layer and an upper part completely excluding Cr element out of the lattice of the Co-based alloy magnetic crystal layer;
• and
• a Co-based alloy non-magnetic crystal layer interposed between the seed crystal layer and the Co-based alloy magnetic crystal layer, said Co-based alloy non-magnetic crystal layer containing Cr element at a first concentration level near the seed crystal layer and at a second concentration level smaller than the first concentration level near the magnetic crystal layer.

A magnetic recording medium comprising:

• a substrate;
• a seed crystal layer formed on a surface of the substrate and containing a non-magnetic element;
• a magnetic crystal layer containing the non-magnetic element diffused along a grain boundary, said magnetic crystal layer including a lower part partly excluding the non-magnetic element out of a lattice of the magnetic crystal layer and an upper part completely excluding the non-magnetic element out of the lattice of the magnetic crystal layer;
• and
• a non-magnetic crystal layer interposed between the seed crystal layer and the magnetic crystal layer, said non-magnetic crystal layer containing the non-magnetic element at a first concentration level near the seed crystal layer and at a second concentration level smaller than the first concentration level near the magnetic crystal layer.