Structure and magnetism of transition‐metal–magnesium thin films with an artificially layered structure

Transition‐metal–magnesium (TM‐Mg) thin films, Fe‐Mg, Co‐Mg, and Ni‐Mg, with an artificially layered structure are formed by the magnetron sputtering method. TM and Mg grow epitaxially on the closest planes in films with a thicker Co layer than a Mg layer. Crystallographic structures of the films are the bcc with the 〈110〉 direction normal to the film plane for Fe‐Mg films, the hcp with the 〈001〉 normal for Co‐Mg films, and the fcc with the 〈111〉 normal for Ni‐Mg films. The films, composed of a monatomic layer of Mg and then several atomic layers of TM in an alternating way, show a clearly separated spot pattern in the reflection high‐energy electron diffraction analysis. The artificial superlattice structure of the films is thermally stable at temperatures up to 700 K. The films composed of a thicker TM layer than a Mg layer are ferromagnetic with an easy magnetization direction in the film plane. The magnetization of TM in all films is smaller than that of the bulk. The paramagnetism or the nonmagnetism...