skip to main content

Title: Fermi level pinning in Fe-doped PbTe under pressure

We synthesize an iron-doped PbTe single-crystal ingot and investigate the phase and the elemental composition as well as galvanomagnetic properties in weak magnetic fields (4.2 K≤T≤300 K, B ≤ 0.07 T) of Pb{sub 1−y}Fe{sub y}Te alloys upon varying the iron content, at atmospheric pressure and under hydrostatic compression up to 10 kilobars. We find an increase of iron concentration along the length of the ingot and the appearance of microscopic inclusions enriched with iron in the heavily doped samples. Lightly doped alloys are characterized by the p-type metal conductivity. An increase of the iron impurity content leads to a decrease in the free hole concentration, a stabilization of galvanomagnetic parameters, indicating the pinning of the Fermi energy by the iron resonant impurity level lying under the bottom of the valence band, and to the p-n inversion of the conductivity type. Under pressure, the free hole concentration in the sample, in which the stabilization of galvanomagnetic parameters takes place, increases by approximately a factor of four due to the flow of electrons from the valence band to the iron-induced resonant level. Using the two-band Kane and the six-band Dimmock dispersion relations, the pressure dependence of the Fermi energy is calculated. The model of the electronic structuremore » rearrangement of Pb{sub 1−y}Fe{sub y}Te under pressure is proposed. The energy position and the pressure coefficient of the resonant iron impurity level are determined.« less
Authors:
; ;  [1] ; ;  [2]
  1. Faculty of Physics, M. V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation)
  2. Institute of Materials Science Problems, National Academy of Sciences of Ukraine, Chernovtsy 58001 (Ukraine)
Publication Date:
OSTI Identifier:
22311076
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALLOYS; CONCENTRATION RATIO; DISPERSION RELATIONS; DOPED MATERIALS; ELECTRONIC STRUCTURE; ELECTRONS; FERMI LEVEL; IMPURITIES; IRON ADDITIONS; LEAD TELLURIDES; MAGNETIC FIELDS; MONOCRYSTALS; PRESSURE DEPENDENCE; STABILIZATION; VISIBLE RADIATION