We show that oscillatory indirect magnetic exchange coupling via transition metals sandwiched between ferromagnetic layers of Fe, Co, Ni, or Ni alloys is a general phenomeonon. Surprisingly, the oscillation period is approximately the same, ≃10 Å, in all the transition metals in which we observe coupling with the single exception of Cr, for which it is much longer. Furthermore, the exchange-coupling strength is found to increase systematically from the 5d to 4d to 3d metals and exponentially with increasing number of d electrons along each period.

• Received 26 April 1991

DOI:https://doi.org/10.1103/PhysRevLett.67.3598