Browsing by Author "Chung, D. Y."

Now showing items 1-17 of 17

    • 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  

      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  

      CsMBi3Te6 and CsM2Bi3Te7 (M = Pb, Sn): New thermoelectric compounds with low-dimensional structures 

      Hsu, K. F.; Chung, D. Y.; Lal, S.; Mrotzek, A.; Kyratsi, Theodora; Hogan, T.; Kanatzidis, M. G. (2002)
      The new materials CsPbBi3Te6 nad CsPb2Bi3Te7 were discovered through reactions of CsBi4Te6 with PbTe, whereas the isostructural materials CsSnBi3Te6 and CsSn2Bi3Te7 were discovered through corresponding reactions with SnTe. ...
    • 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 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  

      Electronic structure of K 2Bi 8Se 13 

      Bilc, D. I.; Mahanti, S. D.; Kyratsi, Theodora; Chung, D. Y.; Kanatzidis, M. G.; Larson, P. (2005)
      K 2Bi 8Se 13 belongs to a class of complex chalcogenides that shows potential for superior thermoelectric performance. This compound forms in two distinct phases, α and β. The β phase, which has several sites with mixed ...
    • 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 ...
    • Conference Object  

      Mechanical alloying synthesis of K2Bi8Se 13- type solid solutions 

      Toumpas, N.; Kyratsi, Theodora; Hatzikraniotis, E.; Tsiappos, A.; Pavlidou, E.; Paraskevopoulos, K. M.; Chung, D. Y.; Kanatzidis, M. G. (Affiliation: Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, 1678, CyprusAffiliation: Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124, GreeceAffiliation: Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, United StatesAffiliation: Department of Chemistry, Northwestern University, Evanston, IL 60208, United StatesCorrespondence Address: Toumpas, N.Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, 1678, Cyprus, 2008)
      Solid solutions of β-K2Bi8-xSb xSe13 are an interesting series of materials for thermoelectric investigations due to their very low thermal conductivity and highly anisotropic electrical properties. In this work, we aimed ...
    • Article  

      Role of K/Bi disorder in the electronic structure of β -K2 Bi8 Se13 

      Hoang, K.; Tomic, A.; Mahanti, S. D.; Kyratsi, Theodora; Chung, D. Y.; Tessmer, S. H.; Kanatzidis, M. G. (2009)
      We have carried out tunneling spectroscopy and first-principles studies for β -K2 Bi8 Se13, a promising thermoelectric material with partially disordered mixed K/Bi sites. The tunneling data, obtained with a scanning ...
    • Article  

      Seebeck and thermal conductivity analysis in amorphous/crystalline β-K2Bi8Se13 nanocomposite materials 

      Kyratsi, Theodora; Hatzikraniotis, E.; Ioannou, M.; Chung, D. Y.; Tsiaoussis, I. (2018)
    • Conference Object  

      Sintering process in ball-milled K2Bi8Se13 nano-composites 

      Ioannou, M.; Hatzikraniotis, E.; Lioutas, C.; Chrissafis, K.; Chung, D. Y.; Paraskevopoulos, K. M.; Kyratsi, Theodora (Affiliation: Department of Mechanical and Manufacturing Engineering, University of Cyprus, 1678 Nicosia, CyprusAffiliation: Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceAffiliation: Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, United StatesCorrespondence Address: Ioannou, M.Department of Mechanical and Manufacturing Engineering, University of Cyprus, 1678 Nicosia, Cyprus, 2012)
      K2Bi8Se13 material has many attractive features for thermoelectric applications. Recently, K2Bi 8Se13 based nanocomposite materials, consisting of nano-crystalline, micro-crystalline and amorphous phases, have been fabricated ...
    • Conference Object  

      Synthesis, crystal structure and thermoelectric properties of β-K 2Bi 8Se 13 solid solutions 

      Kyratsi, Theodora; Chung, D. Y.; Dyck, J. S.; Uher, C.; Lal, S.; Loo, S.; Hogan, T.; Ireland, J.; Kannewurf, C. R.; Hatzikraniotis, E.; Paraskevopoulos, K. M.; Kanatzidis, M. G. (Affiliation: Department of Chemistry, Michigan State University, East Lansing, MI 48824, United StatesAffiliation: Department of Physics, University of Michigan, Ann Arbor, MI 48109, United StatesAffiliation: Department of Electrical Engineering, Michigan State University, East Lansing, MI 48824, United StatesAffiliation: Department of Electrical Engineering, Northwestern University, Evanston, IL 60208, United StatesAffiliation: Department of Physics, Aristotle University of Thessaloniki, 54006 Thessaloniki, GreeceCorrespondence Address: Kyratsi, T.Department of Chemistry, Michigan State University, East Lansing, MI 48824, United States, 2003)
      Solid solution series of the type K 2Bi 8-xSb xSe 13, K 2-xRb xBi 8Se 13 as well as K 2B 18Se 13-xS x were prepared and the distribution of the atoms (Bi/Sb, K/Rb and Se/S) on different crystallographic sites, the band ...
    • Article  

      Thermoelectric module for low temperature applications 

      Lal, S.; Loo, S.; Chung, D. Y.; Kyratsi, Theodora; Kanatzidis, M. G.; Cauchy, C.; Hogan, T. P. (2002)
      The possibility of a prototype thermoelectric cooling device for operation near liquid nitrogen temperatures has been explored. In these devices, the figure of merit involves a combination of the properties of the two ...
    • Article  

      Thermoelectric properties and site-selective Rb+/K+ distribution in the K2-xRbxBi8Se13 series 

      Kyratsi, Theodora; Chung, D. Y.; Ireland, J. R.; Kannewurf, C. R.; Kanatzidis, M. G. (2003)
      β-K2Bi8Se13 possesses promising thermoelectric properties whereas Rb2Bi8Se13 does not. The formation of solid solutions between these two compounds was attempted to study the alkali metal distribution in the structure and ...
    • Conference Object  

      Thermoelectric properties of K2Bi8-xSbxSe13 solid solutions and Se doping 

      Kyratsi, Theodora; Dyck, J. S.; Chen, W.; Chung, D. Y.; Uher, C.; Paraskevopoulos, K. M.; Kanatzidis, M. G. (Affiliation: Department of Chemistry, Michigan State University, East Lansing, MI 48824, United StatesCorrespondence Address: Kyratsi, T.Department of Chemistry, Michigan State University, East Lansing, MI 48824, United States, 2002)
      Our efforts to improve the thermoelectric properties of β-K2Bi8Se13, led to systematic studies of solid solutions of the type β-K2Bi8-xSbxSe13. The charge transport properties and thermal conductivities were studied for ...
    • Conference Object  

      Transport properties of the doped thermoelectric material K2Bi8-xSbxSe13 

      Brazis, P. W.; Ireland, J. R.; Lane, M. A.; Kyratsi, Theodora; Chung, D. Y.; Kanatzidis, M. G.; Kannewurf, C. R. (Affiliation: Dept. of Electrical and Comp. Eng., Northwestern University, Evanston, IL 60208-3118, United StatesCorrespondence Address: Brazis, P.W.Dept. of Electrical and Comp. Eng., Northwestern University, Evanston, IL 60208-3118, United States, 2001)
      The synthesis, physicochemical, spectroscopic, and structural characterization of the compound β-K2Bi8Se13 has been previously reported. The results indicated that this material should be investigated further for possible ...