Ferromagnetic manganese silicide nanoparticles formed by ion implantation in silicon

Manganese silicide nanoparticles (NPs) embedded in silicon were fabricated by an ion implantation method with various manganese ion acceleration energies (E-acc). The NPs were single crystalline with a tetragonal structure and exhibited ferromagnetic properties below the blocking temperature (T-B), at which the magnetization of NPs starts to fall into a metastable state and becomes fixed. T-B increased as E-acc increased. On the basis of Neel's relaxation theory, we revealed that this dependence originates from the influence of E-acc on the particle sizes.