Magnetic hyperfine fields in the room-temperature dilute magnetic semiconducting alloy Fe:Sb1−xSex

Abstract

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 4.2×1019cm−3 to 1.142×1021cm−3 in this region. For higher concentration of Se (X=0.50), the charge carrier densities decreased dramatically to 2.1×1015. 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). Tc (for Site A) was measured to be ∼573K. Similar behavior was observed for Fe(0.002). Site B Mossbauer parameters coincide with those of Fe7Se8.

Magnetic glassy state in combination with ferromagnetism in Fe0.05(SnTe)0.97Sb0.03 bulk alloy

“…The enhanced coercivity value of Fe 0.05 (SnTe) 0.97 Sb 0.03 may seem to be the result of introduction of donor electrons of Sb into the system. Such enhanced magnetism due to donor impurity was also observed in one of our earlier work which was attributed to p-d exchange interaction process (RKKY interaction) [32]. From the hysteresis curve, we also find that the coercivity value has been decreased to 318 Oe as temperature is increased to 300 K.…”