SmCo$_{5}$ With Perpendicular Anisotropy Induced by a (211) Textured Ni$_{4}$ W Underlayer

Abstract

In this work, we have successfully induced SmCo <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> -(0001) texture using the Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> W-(211) underlayer. A tungsten (W) seed layer of 4 nm resulted in a nanocrystalline (211)-textured Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> W underlayer deposited at room temperature. Highly (0001)-textured SmCo <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> was achieved after the sputtering deposition in the temperature range of 500-540°C. The crystallinity of the SmCo <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> layer was reduced at higher deposition temperature (¿ 550°C), probably due to W diffusion. The nano-grained SmCo <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> thin film deposited at 500°C shows an out-of-plane coercivty of 12.7 kOe with a large perpendicular magnetic anisotropy. The thickness of Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> W underlayer can be reduced to 13 nm without a significant change in the large perpendicular magnetic coercivity of the SmCo <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> thin film.