Paper MI-ThM9
Structural and Magnetic Properties of Mn-implanted 3C-SiC

Thursday, October 18, 2007, 10:40 am, Room 619

Unlike many Dilute Magnetic Semiconductors particularly Si based ones,¹ very little attention has been paid to SiC despite its potential for high-power, high-temperature electronics and its large compatibility with the mature Si technology. With its wide bandgap, excellent transport properties and dopability, it might be a promising candidate for spintronic applications. Due to a limited solubility of Mn in the host SiC materials, we have used Mn+ implantation (energy of 80 keV and dose of 5x1015 cm^-2) to achieve higher Mn atomic concentration of 1.8 % in micrometric thick 3C-SiC films; aiming to enhance the Curie temperature. We have used Rutherford backscattering (RBS) and X-ray diffraction (XRD) techniques to asses the defects introduced by Mn–implantation, as well as magnetometry to investigate the magnetic properties. RBS measurements on single SiC indicate high concentration of defects at a depth of about 45 nm from the surface, with Mn randomly distributed in the host SiC material. XRD spectra show no indication of formation of secondary alloying phase. Both single and polycrystalline implanted samples were found to be ferromagnetic at room temperature with a magnetic moment per Mn atom of about 0.37μB and 0.5μB, respectively. The amorphous layer was recrystallized after annealing at 750 °C for 10 min as indicated by RBS results, yielding an enhancement of magnetic moment. First principle calculation using Full-Potential Linearized-Augmented-Plane-Wave method for different environments and vacancy configurations was performed to better understand and establish a correlation between the structure/microstructure and magnetic properties of single and polycrystalline Mn-implanted 3C-SiC.

¹M. Bolduc et al., Phys. Rev. B 71 (2005) 033302.