Electric and magnetic characterization of impurity-induced states in diluted magnetic Pb1−yYbyTe semiconductors

Electrical and thermoelectric properties of PbSe doped with Sm

“…The results extracted that, the absolute value of S of PbSe samples are varying between 0.2 and 0.257 mV/K which is around previous published data [18,48]. The general trend is the enhancement of the absolute value of Seebeck coefficient with Sm enriching [29] and the highest value is possessed for Pb 0.94 Sm 0.06 Se composition. The reduction of |S| which associates the annealing time prolongation may be attributed to enlarging the grain size which implies a decrease in the number of grain boundaries [18,49].…”

“…It is clear that the activation energy for a certain composition decreases with elevating the annealing time from 160 to 240 min. However, its increase with increasing the magnetic ions (Sm) content is due to the impurity level movement into the forbidden gap [29,[30][31][32]. In Fig.…”

“…Doping with these elements transforms IV-VI semiconductors into semimagnetic semiconductors [21][22][23][24][25][26][27][28]. In the other side, Skipetrov et al [29] reported that ytterbium doping modifies the energy spectrum of charge carriers in lead telluride by formation of deep impurity level. At low Ytterbium content this deep level is resonant with the valence band, however by increasing the impurity concentration it approaches the valence band edge and shifts into the forbidden band.…”

Impurity‐related magnetism in the diluted magnetic semiconductors Pb1−xSnxTe:Yb

“…Since the first reports on magnetic measurements in ytterbium-doped PbTe-based alloys it has been known that doping with Yb induces an appearance of the impurity-related paramagnetic response due to the presence of the magnetically active Yb 3+ ions in the materials [10,11]. Substituting the metal in a host semiconductor lattice, an ytterbium atom can contribute as either an electrically neutral and non-magnetic Yb 2+ (4f 14 ) ion or an electrically and magnetically active Yb 3+ (4f 13 ) ion. It is also known that ytterbium doping leads to the emergence of a donor impurity level E Yb , that in PbTe pins the Fermi level slightly under the valence-band top.…”

“…It is also known that ytterbium doping leads to the emergence of a donor impurity level E Yb , that in PbTe pins the Fermi level slightly under the valence-band top. An increase of the Ge or Yb content in the PbTe-based alloys results in the shift of the ytterbium level from the valence band to the gap and induces redistribution of the charge carriers between localized and band states [12,13]. Under these conditions the magnetic properties of the alloys are determined not only by the concentration of impurity introduced but also by the occupancy of the Yb-induced level and hence by the mutual arrangement of valence and impurity-induced bands [13,14].…”