Structural and magnetic properties of Mn-implanted Si

Structural and magnetic properties in Mn-implanted, $p$-type Si were investigated. High resolution structural analysis techniques such as synchrotron x-ray diffraction revealed the formation of $\mathrm{Mn}{\mathrm{Si}}_{1.7}$ nanoparticles already in the as-implanted samples. Depending on the Mn fluence, the size increases from $5\mathrm{nm}\text{to}20\mathrm{nm}$ upon rapid thermal annealing. No significant evidence is found for Mn substituting Si sites either in the as-implanted or annealed samples. The observed ferromagnetism yields a saturation moment of $0.21{\mu }_{\mathrm{B}}$ per implanted Mn at $10\mathrm{K}$, which could be assigned to $\mathrm{Mn}{\mathrm{Si}}_{1.7}$ nanoparticles as revealed by a temperature-dependent magnetization measurement.