Ferromagnetic Resonance In Cozr/Ag/Cozr Trilayer Films

A series of CoZr(200 Angstrom)/Ag(t(Ag))/CoZr(200 Angstrom) trilayers with Ag interlayer thickness t(Ag) in the range of 10-160 Angstrom was deposited on Si(100)-wafers at room temperature by using a magnetron sputtering system. In order to understand the dependence of the magnetic exchange interaction between ferromagnetic Co84Zr16(at.%) layers separated by nonmagnetic Ag layer on the t(Ag), we investigated the FMR spectra. The coupling strength increases with increasing t(Ag) up to 20 Angstrom with a maximum value of 2.0 kOe, but decreases rapidly with increasing t(Ag) in the range of 40-100 Angstrom. Finally, the value approaches zero above 120 Angstrom. The coupling strength is positive for all samples.