Thermoelectric properties of ternary and Al-containing quaternary Ru1-xRexSiy chimney-ladder compounds

• KISHIDA K.

Abstract

The thermoelectric properties of ternary and Al-containing quaternary Ru1−xRexSiy chimney–ladder phases have been studied as a function of the Re concentration with the use of directionally solidified alloys. The Ru1−xRexSiy chimney–ladder phases exhibit n- and p-type semiconducting behaviors, respectively, at low and high Re concentrations, at which the X(=Si)/M(=Ru + Re) ratios are respectively, larger and smaller than those expected from the VEC (valence electron concentration) = 14 rule. The absolute values of both Seebeck coefficient and electrical resistivity increase as the extent of the deviation from the VEC = 14 rule increases, i.e. as the alloy composition deviates from that corresponding to the p–n transition (x ≈ 0.5), indicating that the carrier concentration can be controlled by changing the extent of compositional deviation from the ideal VEC = 14 composition. The highest values of the dimensionless figure of merit obtained are 0.47 for ternary (x = 0.60) and 0.56 for Al-containing quaternary alloys. The reasons for the systematic compositional deviation from the ideal VEC = 14 compositions observed for a series of chimney–ladder phases are discussed in terms of atomic packing.

Journal

• Acta Materialia

  Acta Materialia 57 (6), 2010-2019, 2009-04

  Elsevier

Keywords

• Transition metal silicides
• Thermoelectric
• Crystal structure
• Electron diffraction
• Semiconductor compounds

Details

• CRID: 1571980076407847936
• NII Article ID: 80020243003
• NII Book ID: AA1106787X
• ISSN: 13596454
• Web Site: http://hdl.handle.net/2433/123375
• Text Lang: en
• Data Source:
  • CiNii Articles