1995 Volume 19 Issue 68 Pages 35-42
Elemental segregations of CoCrTa thin films for longitudinal and perpendicular media are investigated using high spacial resolution transmission electron microscopes equipped with compositional analysis facilities. Strong Cr segregations exceeding 25 at% are observed at grain boundaries for both types of CoCrTa films prepared at elevated substrate temperatures. The thickness of the Cr-enriched layer is estimated to be 1.5 -2nm. The Cr segregation at bi-crystalline boundary observed for a longitudinal CoCrTa film is lower than that observed at normal grain boundary. The Cr concentraion inside the magnetic crystal grain is ranging between 6 and 12 at.% which is lower than the average Cr composition. The strong Cr segregations are correlated with the high coercivity of CoCrTa perpendicular medium.
