Structure and magnetic properties of Fe/Zr multilayers

Fe/Zr multilayers with wedge-shaped Fe or Zr sublayers were prepared using UHV (5 × 10−10 mbar) DC/RF magnetron sputtering. The planar growth of the Fe and Zr layers was confirmed in situ by X-ray photoelectron spectroscopy. Iron sublayers grow on sufficiently thick zirconium (dZr > 0.7 nm) sublayers in the soft magnetic nanocrystalline phase up to a critical thickness dcrit ∼ 2.3 nm. For a thickness greater than dcrit, the Fe sublayers undergo a structural transition to the polycrystalline phase with much higher coercivity.