Local structures in Pb_1−xMn_xTe systems

XAFS studies of nickel-doped lead telluride

“…Even though long-range Coulomb interaction is expected to be strongly screened in PbTe compound due to the large dielectric constant, the Ni-Ni interaction is still strong enough to bring Ni atoms close to each other, even at this small concentration. Similar situation is observed in PbTe:Mn, only the transformation of the Mn immediate surrounding to MnTe was not completed which resulted in Mn off-centering from the regular PbTe lattice position [15,17]. Definite answers about Ni doping effects on PbTe will be possible to obtain after completing the Te K-edge data analysis.…”

“…The near edge region of the absorption spectrum (XANES) is sensitive on electronic structure and contains information on oxidation state and the local coordination geometry around the absorbing atom, whereas the high energy region (EXAFS) is associated with the arrangement of atoms and provides information about the short range order in terms of number, type and distances of atoms in coordination shells and their disorder parameters. Using XAFS spectroscopy we have already resolved the local structures in the series of lead telluridebased semiconductors [15][16][17]. In this work we extend our studies to Ni-doped PbTe, a semimagnetic semiconductor whose electronic and magnetic properties are not completely understood.…”

Local, electronic and surface structure of multi-component Fe-doped CdTe(S) systems

“…Samples were oriented at 45° with respect to the incident beam and a 7-segment Ge-detector was used to collect the spectra at T= 10 K and 293 K. Multiple scans were taken to improve signal-to-noise ratio. Data processing and analysis were performed using ATHENA and ARTEMIS packages [26], according to the standard procedure described elsewhere [27]. In the fitting procedure following parameters were varied: the mean distance of the j th shell (R j ), the number of atoms in the j th shell (N j ), the mean-squared displacement of atoms in the j th shell (σ j 2 ), and the single edge shift correction (ΔE 0 ).…”

XAFS studies of ytterbium doped lead-telluride

“…This change of the Yb valence state is ascribed to change of the f-shell occupancy, from 14 electrons in Yb 2+ to 13 electrons in Yb 3+ state (4f 13 5d 1 6s 2 ), and is accompanied with charge redistribution in the local surrounding of the impurity atom. A significant distortion of the host structure around impurities was already observed in numerous PbTe-based compounds [11,12].…”