Ferromagnetic and ordered MnSi(111) epitaxial layers

We report a comprehensive study of ordered MnSi films grown on Si(111) which provides clear proofs that these MnSi films have the same magnetic and electronic properties of bulk MnSi compound, so closing a long-standing question. Furthermore, our measurements show the presence of a room-temperature ferromagnetic transition consistent with the ferromagnetic ground state predicted for Mn atoms with reduced coordination near surfaces and interfaces of silicon by recent calculations of Hortamani et al. [Phys. Rev. B 78, 104402 (2008)]. The possibility of growing layers on semiconductors which are ferromagnetic at room temperature (RT) is of paramount importance for nonvolatile memories and spintronic devices based on the injection of spin-polarized current from a ferromagnetic metal into a semiconductor. In this perspective MnSi films grown on Si substrates represent an interesting case study.