Microstructural, surface morphological, and magnetic properties of oblique angle deposited Co thin films on ion-beam fabricated self-organized Si substrates

Abstract

The microstructural, surface morphological, and magnetic properties of Co thin films grown, under oblique angle deposition, on low energy (500 eV) ion-beam fabricated self-organized rippled-Si substrates are presented. All films show the hexagonal-close-packed structure with the majority of the Co grains oriented along the (101‾2) and (0002) directions. Interestingly, Co film morphology follows the underlying ripple topography up to a thickness of 15 nm, whereas the conformal growth disappears at higher thicknesses (viz. 30 and 60 nm). The thicker films show the signature of tilted columnar structures. Further, a strong uniaxial magnetic anisotropy is observed for all films with the easy axis of magnetization perpendicular to the direction of the ripple wave vector.