High-temperature diamond-like Si-based ferromagnet with self-organized superlattice distribution of Mn impurity

The crystal structure of nanofilms of a Si:Mn dilute magnetic semiconductor with the Curie temperature of about $500$ K obtained by the pulsed deposition from a laser plasma has been studied by high-resolution electron microscopy and diffraction. The ferromagnetism of Si:Mn characterized by high electrical and complete magnetic activities of Mn manifests itself in the ferromagnetic resonance, anomalous Hall effect, and magneto-optic Kerr effect. It is shown that the nonequilibrium laser technique allows achieving a pronounced supersaturation of the Mn solid solution as high as $15\%$. In such solutions, Mn substitutes silicon, leaving unchanged the diamond-like crystal structure and does not prevent the epitaxial growth of Si:Mn films. At the same time, there occurs a self-organized formation of the superlattice structure with the period equal to triple the distance between the nearest (110) atomic layers, where (110) layers doped with Mn are oriented along the growth direction of the Si:Mn film.