A perpendicularly magnetized ferromagnetic layer is an important building block for recent/future high-density spintronic memory applications. This paper reports the fabrication of perpendicularly magnetized Ni/Pt superlattices and the characterization of their structures and magnetic properties. The optimization of film growth conditions allowed us to grow epitaxial Ni/Pt (001) superlattices on $\mathrm{SrTi}{\mathrm{O}}_3$ (001) single-crystal substrates. We investigated their structural parameters and magnetic properties as a function of the Ni layer thickness and obtained a high uniaxial magnetic anisotropy energy of $1.9\times {10}^6\mathrm{erg}/\mathrm{c}{\mathrm{m}}^3$ for a [Ni (4.0 nm)/Pt (1.0 nm)] superlattice. In order to elucidate the detailed mechanism on perpendicular magnetic anisotropy for the Ni/Pt (001) superlattices, the experimental results were compared with the first-principles calculations. It has been found that the strain effect is a prime source of the emergence of perpendicular magnetic anisotropy.

• Received 28 January 2020
• Accepted 29 May 2020

DOI:https://doi.org/10.1103/PhysRevMaterials.4.064413