Formation mechanism of ferromagnetism in Si1-xMnx diluted magnetic semiconductors

Si1-xMnx diluted magnetic semiconductor (DMS) bulks were formed by using an implantation and annealing method. Energy dispersive X-ray fluorescence, transmission electron microscopy (TEM), and double-crystal rocking X-ray diffraction (DCRXD) measurements showed that the grown materials were Si1-xMnx crystalline bulks. Hall effect measurements showed that annealed Si1-xMnx bulks were p-type semiconductors. The magnetization curve as a function of the magnetic field clearly showed that the ferromagnetism in the annealed Si1-xMnx bulks originated from the interaction between interstitial and substitutional Mn+ ions, which was confirmed by the DCRXD measurements. The magnetization curve as a function of the temperature showed that the ferromagnetic transition temperature was approximately 75 K. The present results can help to improve understanding of the formation mechanism of ferromagnetism in Si1-xMnx DMS bulks. (C) 2005 Elsevier Ltd. All rights reserved.