Spin engineering in ultrathin Co0.35Pd0.65 alloy films

The easy axis of magnetization in CoxPd1-x alloy films with x=0.35 is contr ollably engineered by varying the thickness, t(Pd), of the Pd overlayers di rectly deposited on the alloy layers. In a Pd(50 Angstrom)/CoPd (20 Angstro m)/Pd (t(Pd)) sample with a 10-A-height step-wedge Pd layer, the easy axis smoothly changes from in-plane orientation (t(Pd)=0 Angstrom) through cante d out of plane (0 <t(Pd)< 30 Angstrom) to perpendicular (30 less than or eq ual tot(Pd)less than or equal to 60 Angstrom). We also demonstrate that the spin switching is controllably reversible between in-plane and perpendicul ar orientations when the individual constituent layers of CoPd and Pd are a lternately deposited. Smoothly continuous spin reorientation in a Pd (50 An gstrom)/CoPd (30 Angstrom)/Pd (t(Pd)) film with increasing t(Pd) in a broad range of 0-150 Angstrom convincingly evidences the magnetoelastic anisotro py origin for the observed spin switching. (C) 2001 American Institute of P hysics.