Browsing by Subject "Thermoelectricity"

Now showing items 1-20 of 34

    • Article  

      Bi/Sb distribution and its consequences in solid solution members of the thermoelectric materials K2Bi8-xSbxSe13 

      Kyratsi, Theodora; Chung, D. Y.; Kanatzidis, M. G. (2002)
      In an effort to understand the nature of mass fluctuations introduced when β-K2Bi8Se13 is alloyed with K2Sb8Se13 we determined the detailed crystal structures of two solid solutions of the type K2Bi8-xSbxSe13 with x=4.0 ...
    • 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 ...
    • Conference Object  

      Crystal growth of ternary and quaternary alkali metal bismuth chalcogenides using Bridgman technique 

      Kyratsi, Theodora; Chung, D. Y.; Choi, K.-S.; Dick, J. S.; Chen, W.; Uher, C.; Kanatzidis, M. (Affiliation: Dept. of Chemistry, Center of Fundamental Mat. Research, Michigan State University, East Lansing, MI 48824-1322, United StatesCorrespondence Address: Kyratsi, T.Dept. of Chemistry, Center of Fundamental Mat. Research, Michigan State University, East Lansing, MI 48824-1322, United States, 2001)
      Our exploratory research in new thermoelectric materials has identified the ternary and quaternary bismuth chalcogenides β-K2Bi8Se13, K2.5Bi8.5Se14 and K1+xPb4-2xBi7+xSe15, to have promising properties for thermoelectric ...
    • Article  

      Design of ball-milling experiments on Bi2Te3 thermoelectric material 

      Kanatzia, A.; Papageorgiou, Ch; Lioutas, Ch; Kyratsi, Theodora (2013)
      In this work, factorial ball-milling experiments have been applied to Bi2Te3 material, for the first time, aiming to investigate the effect of the main process parameters on the structural features and thermoelectric ...
    • Article  

      Design, assembly and characterization of silicide-based thermoelectric modules 

      Skomedal, G.; Holmgren, L.; Middleton, H.; Eremin, I. S.; Isachenko, G. N.; Jaegle, M.; Tarantik, K.; Vlachos, N.; Manoli, M.; Kyratsi, Theodora; Berthebaud, D.; Truong, N. Y. Dao; Gascoin, F. (2016)
      Silicides have attracted considerable attention for use in thermoelectric generators due mainly to low cost, low toxicity and light weight, in contrast to conventional materials such as bismuth and lead telluride. Most ...
    • Conference Object  

      Doping and alloying trends in new thermoelectric materials 

      Loo, S.; Lal, S.; Kyratsi, Theodora; Chung, D. Y.; Hsu, K. F.; Kanatzidis, M. G.; Hogan, T. P. (Affiliation: Dept. of Elec. and Comp. Engineering, Michigan State University, East Lansing, MI, United StatesCorrespondence Address: Loo, S.Dept. of Elec. and Comp. Engineering, Michigan State University, East Lansing, MI, United States, 2002)
      New thermoelectric bulk materials such as CsBi4Te6 have shown superior properties to traditional materials, however, optimal performance requires continuing investigations of doping and alloying trends. A recently modified ...
    • Conference Object  

      Doping studies of n-type CsBi4Te6 thermoelectric materials 

      Lane, M. A.; Ireland, J. R.; Brazis, P. W.; Kyratsi, Theodora; Chung, D. Y.; Kanatzidis, M. G.; Kannewurf, C. R. (Affiliation: Dept of Electrical and Computer Eng., Northwestern University, Evanston, IL 60208, United StatesCorrespondence Address: Lane, M.A.Dept of Electrical and Computer Eng., Northwestern University, Evanston, IL 60208, United States, 2001)
      We have previously reported the successful p-type doping of CsBi4Te6 which had a high figure of merit at temperatures below 300 K. In this study, several dopants were explored to make n-type CsBi4Te6. A program of measurements ...
    • 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 ...
    • Article  

      Effect of microstructure on the thermoelectric performance of La1−xSrxCoO3 

      Viskadourakis, Z.; Athanasopoulos, G. I.; Kasotakis, E.; Giapintzakis, John (2016)
      We present a case where the microstructure has a profound effect on the thermoelectric properties of oxide compounds. Specifically, we have investigated the effect of different sintering treatments on La1−xSrxCoO3 samples ...
    • Article  

      Effect of silicon nitride/oxide on the structure and the thermal conductivity of CoSi nanocomposites 

      Ioannou, M.; Delimitis, A.; Symeou, E.; Giapintzakis, John; Kyratsi, Theodora (2017)
      In this work, the fabrication of nanocomposites with silicon nitride/oxide into the thermoelectric matrix of cobalt silicide is presented. The different concentrations of nano-Si3N4 were intentionally introduced by mechanical ...
    • Article  

      Effect of sintering in ball-milled K 2Bi 8Se 13 thermoelectric nano-composites 

      Hatzikraniotis, E.; Ioannou, M.; Chrissafis, K.; Chung, D. Y.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2012)
      K 2Bi 8Se 13 has many attractive features for thermoelectric applications. Recently, K 2Bi 8Se 13-based nanocomposite materials, consisting of nano-crystalline, micro-crystalline and amorphous phases, have been fabricated ...
    • Article  

      Efficiency study of a commercial thermoelectric power generator (TEG) under thermal cycling 

      Hatzikraniotis, E.; Zorbas, K. T.; Samaras, I.; Kyratsi, Theodora; Paraskevopoulos, K. M. (2010)
      Thermoelectric generators (TEGs) make use of the Seebeck effect in semiconductors for the direct conversion of heat to electrical energy. The possible use of a device consisting of numerous TEG modules for waste heat ...
    • Article  

      Electronic Structure and Thermoelectric Properties of Pseudoquaternary Mg2Si1-x-ySnxGey-Based Materials 

      Kutorasinski, K.; Tobola, J.; Kaprzyk, S.; Khan, A. U.; Kyratsi, Theodora (2014)
      A theoretical study is presented on complex pseudoternary Bi-doped Mg2Si1-x-ySnxGey materials, which have recently been revealed to reach high thermoelectric figures of merit (ZT) of ∼1.4. Morphological characterization ...
    • Article  

      Fabrication of nanocrystalline Mg 2Si via ball milling process: Structural studies 

      Ioannou, M.; Hatzikraniotis, E.; Lioutas, C.; Hassapis, T.; Altantzis, T.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2012)
      In this work, nanocrystalline Mg 2Si material was fabricated via wet ball milling process using n-hexane as process control agent. Milling parameters, with emphasis on milling time and ball size, and conditions were studied ...
    • Article  

      High thermoelectric figure of merit of Mg2Si 0.55Sn0.4Ge0.05 materials doped with Bi and Sb 

      Khan, A. U.; Vlachos, N.; Kyratsi, Theodora (2013)
      Thermoelectric properties of new Bi- and Sb-doped Mg2Si 0.55Sn0.4Ge0.05 compounds prepared by powder methods were studied in the temperature range 300-823 K. The materials exhibited compositional inhomogeneites consisting ...
    • Article  

      Highly anisotropic crystal growth and thermoelectric properties of K 2Bi 8-xSb xSe 13 solid solutions: Band gap anomaly at low x 

      Kyratsi, Theodora; Dyck, J. S.; Chen, W.; Chung, D. Y.; Uher, C.; Paraskevopoulos, K. M.; Kanatzidis, M. G. (2002)
      The thermoelectric properties of solid solutions of the type β-K 2Bi 8-xSb xSe 13 (0<x<8) were studied with respect to thermal behavior, band gap variation, and charge transport properties as a function of x. At x values ...
    • Article  

      La0.95Sr0.05Coo3: An efficient room-temperature thermoelectric oxide 

      Andrbulakis, J.; Migiakis, P.; Giapintzakis, John (2004)
      Electric resistivity, thermal conductivity, and the thermopower of polycrystalline Sr-doped LaCoO3 with composition La 0.9Sr0.5CoO3 were measured. The crystal structure of the synthesized powders was determined by x-ray ...
    • Article  

      Low-temperature synthesis and thermoelectric properties of n-type PbTe 

      Papageorgiou, C.; Giapintzakis, John; Kyratsi, Theodora (2013)
      n-Type PbTe compounds were synthesized at temperatures as low as 430 C. After synthesis, the materials were ground, cold pressed and sintered at 600 C. The effect of this low-temperature synthesis on the structural features ...
    • Conference Object  

      Modeling of thermal conductivity in high performing thermoelectric materials 

      Hatzikraniotis, E.; Kyratsi, Theodora; Paraskevopoulos, K. M. (Institute of Physics Publishing, 2017)
      The enhanced TE-performance in Mg2Si-Mg2Sn based pseudo-binaries is presented, which is attributed to low thermal conductivity. Sn-Si alloying, reduces the lattice thermal conductivity due to mass fluctuation. Furthermore, ...