It was noted that the partial re-ordering of heavily milled intermetallic alloys resulted in the creation of structurally and chemically ordered nanometric grains which were separated by structurally and chemically disordered grain boundaries. In the case of systems with disorder-induced ferromagnetism, this produced a peculiar magnetic microstructure in which paramagnetic grains were separated by magnetically ordered (ferromagnetic) grain boundaries. This unusual microstructure permitted the easy separation of the magnetic contribution arising from the grain boundaries. This contribution was found to be equal to about 15%; thus suggesting that the grain boundary was a few atomic layers thick. This result was in agreement with high-resolution transmission electron microscopic observations.

Tailoring of Paramagnetic (Structurally Ordered) Nanometric Grains Separated by Ferromagnetic (Structurally Disordered) Grain Boundaries - Isolating Grain-Boundary Magnetic Effects. X.Amils, J.Nogués, S.Suriñach, J.S.Muñoz, M.D.Baró, A.Hernando, J.P.Morniroli: Physical Review B, 2001, 63[5], 052402 (4pp)