Magnetic hyperfine fields in the room-temperature dilute magnetic semiconducting alloy Fe:Sb1-xSex -: art. no. 242508

A dilute quantity of Fe (0.008) was doped into V-VI (Sb1-xSex) for X=0 to 0.50 alloys based on Sb semimetal. Hall measurements showed that the materials were n-type semiconductors for X=0.01 to 0.10 and the charge carrier densities increased from 4.2x10(19) cm(-3) to 1.142x10(21) cm(-3) in this region. For higher concentration of Se (X=0.50), the charge carrier densities decreased dramatically to 2.1x10(15). For X=0, Fe showed no magnetic moment. For X=0.01 to 0.1 two magnetic sites (A and B) were observed at room temperature by Mossbauer measurement. Site A appears to be an SeFeSb, type ternary alloy. p-d interaction and carrier-induced polarization seem to be responsible for the magnetic interaction at this site (A). T-c (for Site A) was measured to be similar to 573 K. Similar behavior was observed for Fe(0.002). Site B Mossbauer parameters coincide with those of Fe7Se8.