Spin Waves Excitations of Co/Pt Multilayers

Abstract

The present work investigated interlayer couplings of [Co(20 Å)/Pt(30 Å)]5, [Co(4 Å)/Pt(7 Å)]30, and [Co(4 Å)/Pt(9 Å)]30multilayers with strong perpendicular magnetic anisotropy (PMA). Brillouin light scattering measurements were utilized to obtain spin waves of these samples with in-plane external magnetic fields. Interlayer couplings were found to be very sensitive to Pt thickness change from 7 Å to 9 Å, which implies that Pt atoms were more difficult to be polarized to provide interlayer coupling between Co layers than in the perpendicular external magnetic field situation. When Pt layer is 30 Å, the observed single spin wave can confirm the disappearance of interlayer coupling even when Co layer thickness is 20 Å.