Identification of substitutional and interstitial Fe in 6H-SiC

Iron impurities on interstitial (Fe-i) and substitutional sites (Fe-S) in SiC have been detected by Fe-57 emission Mossbauer spectroscopy following implantation of radioactive Mn-57(+) parent ions. At temperatures < 900 K two Fe-i species are found, assigned to quasi-tetrahedral interstitial sites surrounded by, respectively, four C (Fe-i,Fe-C) or Si atoms (Fe-i,Fe-Si). Above 900 K, the Fe-i,Fe-Si site is proposed to 'transform' into the Fe-i,Fe-C site by a single Fe-i jump during the lifetime of the Mossbauer state (T-1/2 = 100 ns). Fe-i,Fe-C and substitutional Fe-S sites are stable up to > 1,070 K.