Effect of Grain Size and Pb Doping on the Thermoelectric Properties of Extruded Samples of the Bi0.85Sb0.15 Solid Solution

Tağıyev M.

Inorganic Materials, vol.57, no.2, pp.113-118, 2021 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 57 Issue: 2
  • Publication Date: 2021
  • Doi Number: 10.1134/s0020168521020138
  • Journal Name: Inorganic Materials
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.113-118
  • Keywords: electrical conductivity, extrusion, impurity, solid solution, texture
  • Azerbaijan State University of Economics (UNEC) Affiliated: Yes

Abstract

Abstract—: Electrical and thermal parameters of extruded samples of the Bi0.85Sb0.15 solid solution have been studied as functions of grain size, annealing conditions, Pb acceptor dopant concentration, and magnetic field strength in the temperature range ~77–300 K. The results demonstrate that extrusion of polycrystalline Bi0.85Sb0.15 material produces an axial texture; that is, some of the grains in the polycrystal become aligned so that their trigonal axis is parallel to the extrusion axis. Concurrently, plastic deformation produces various structural defects in the crystal lattice of individual grains. The structural defects accumulate predominantly between (111) cleavage planes of the crystals. The texture of the samples has been shown to depend on grain size. Doping Bi0.85Sb0.15 samples of grain size d ~ 630 μm with Pb acceptor impurities and annealing them at ~503 K for 5 h, we have obtained n-type materials with a thermoelectric figure of merit of ~5 × 10–3 K–1 at ~200 K.