Influence of Pt underlayer and substrate temperature on oriented growth of L10 FePt/MgO (110) thin films

摘要

C-axis oriented L10 FePt thin films have gained a lot of interest for its application in perpendicular magnetic recording media. High switching field (SF) and wide SF distribution caused by even slight changes in magnetic easy axis of grains are major concerns. According to Stoner-Wohlfarth model which describes magnetic reversal behavior of uniaxial single domain ferromagnetic particle, L10 FePt thin film with tilted easy axes of the grains can be applied to reduce SF and make it insensitive to orientation variation. The ideal tilting angle is 45?, which is corresponding to (101) oriented growth of L10 FePt and can maximum the reduction of SF to 50%. However, mixed orientation of (101) and (110) can be found when FePt is deposited on MgO (110) substrate. Energetically, (101) oriented film will have lower surface energy, thus the influence of introducing Pt buffer layer and adjusting substrate temperature during deposition is studied to promote (101) oriented growth.