Browsing by Author "Polymeris, G. S."

Now showing items 1-9 of 9

    • Conference Object  

      Carrier mapping in thermoelectric materials 

      Polymeris, G. S.; Hatzikraniotis, E.; Stefanaki, E. C.; Pavlidou, E.; Kyratsi, Theodora; Paraskevopoulos, K. M.; Kanatzidis, M. G. (Affiliation: Physics Department, Aristotle University of Thessaloniki, GR- 54124, Thessaloniki, GreeceAffiliation: Department of Mechanical and Manufacturing Engineering, University of Cyprus, 1678 Nicosia, CyprusAffiliation: Department of Chemistry, Northwestern University, 2145 North Sheridan Road, Evanston, IL 60208, United StatesCorrespondence Address: Physics Department, Aristotle University of Thessaloniki, GR- 54124, Thessaloniki, Greece, 2013)
      The application of micro-fourier transform infrared (FT1R) mapping analysis to thermoelectric materials towards identification of doping inhomogeneities is described. Micro-FTIR, in conjunction with fitting, is used as ...
    • Article  

      Effect of antimony-doping and germanium on the highly efficient thermoelectric Si-rich-Mg2(Si,Sn,Ge) materials 

      Vlachos, N.; Polymeris, G. S.; Manoli, M.; Hatzikraniotis, E.; Khan, A. U.; Lioutas, C. B.; Stefanaki, E. C.; Pavlidou, E.; Paraskevopoulos, K. M.; Giapintzakis, John; Kyratsi, Theodora (2017)
      Two series of materials (a) Mg2Si0.55-ySn0.4Ge0.05Sby, 0 ≤ y ≤ 0.0175 and (b) Mg2Si0.5875-xSn0.4GexSb0.0125, 0 ≤ x ≤ 0.20 have been developed and studied in terms of structural features and thermoelectric properties/performance. ...
    • Article  

      Effect of Bi-doping and Mg-excess on the thermoelectric properties of Mg2Si materials 

      Ioannou, M.; Polymeris, G. S.; Hatzikraniotis, E.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2014)
      In this work, Bi-doped magnesium silicide compounds were prepared by applying a combination of both, short-time ball milling and heating treatment. The effect of Mg excess was also studied, aiming towards further improvement ...
    • Conference Object  

      Experimental and modeling evidence for the reduction of thermal conductivity in Mg2Si by fine tuning the nano & micro-structural features 

      Hatzikraniotis, E.; Polymeris, G. S.; Symeou, E.; Kyratsi, Theodora; Paraskevopoulos, K. M. (Elsevier Ltd, 2017)
      In this paper, experimental and modeling evidence for reduced thermal conductivity in Bi-doped Mg2Si is presented. Upon doping, lattice thermal conductivity was reduced monotonically and, at the same time, MgO content was ...
    • Article  

      Inhomogeneities and Effective Mass in Doped Mg2Si 

      Stefanaki, E. C.; Polymeris, G. S.; Ioannou, M.; Pavlidou, E.; Hatzikraniotis, E.; Kyratsi, Theodora; Paraskevopoulos, K. M. (2016)
      Magnesium silicide (Mg2Si)-based materials are promising candidates as thermoelectric components for mid-temperature range (500–900 K) energy conversion. Many different approaches for determining the parabolicity of the ...
    • Article  

      Macro and Micro-Scale Features of Thermoelectric PbTe (Br, Na) Systems: Micro-FTIR Spectroscopy, Micro-Seebeck Measurements, and SEM/EDX Observations 

      Stefanaki, E. C.; Polymeris, G. S.; Nikolic, P. M.; Papageorgiou, C.; Pavlidou, E.; Hatzikraniotis, E.; Kyratsi, Theodora; Paraskevopoulos, K. M. (2014)
      In this work, n-type and p-type PbTe doped with Br and Na, respectively, were thoroughly examined to determine the effect of the dopant on microstructure. Macro and micro homogeneity of the samples were studied by means ...
    • Article  

      Nanostructure and doping stimulated phase separation in high-ZT Mg2Si0.55Sn0.4Ge0.05 compounds 

      Polymeris, G. S.; Vlachos, N.; Khan, A. U.; Hatzikraniotis, E.; Lioutas, C. B.; Delimitis, A.; Pavlidou, E.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2015)
      A study was attempted on the structural properties across all relevant length-scales for Mg2(Si,Sn,Ge)-type solid solutions of the formula Mg2Si0.55- ySn0.40Ge0.05(Bi,Sb)y. The study focuses on three families of samples, ...
    • Article  

      Thermoelectric properties of highly efficient Bi-doped Mg2Si1−x−ySnxGey materials 

      Khan, A. U.; Vlachos, N. V.; Hatzikraniotis, E.; Polymeris, G. S.; Lioutas, Ch B.; Stefanaki, E. C.; Paraskevopoulos, K. M.; Giapintzakis, John; Kyratsi, Theodora (2014)
      In this work, Bi-doped Mg2Si1−x−ySnxGey (x=0.4 and y=0.05) solid solutions with the nominal Bi content of 0⩽z⩽0.035 were synthesized by solid state synthesis and sintering via hot pressing, and were studied in terms of ...
    • Article  

      Thermoelectric properties of Mg2Si coatings deposited by pack cementation assisted process on heavily doped Si substrates 

      Stathokostopoulos, D.; Stefanaki, E. C.; Ioannou, M.; Polymeris, G. S.; Chaliampalias, D.; Pavlidou, E.; Kyratsi, Theodora; Paraskevopoulos, K. M.; Vourlias, G.; Hatzikraniotis, E. (2014)
      This work presents a study of structural and thermoelectric properties of Mg2Si coatings deposited on heavily doped p- and n-type Si substrates, at 650 C. The as-grown layers were smooth and uniform in thickness without ...