• 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  

      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 ...
    • 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  

      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  

      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 ...
    • Conference Object  

      Long-term performance of a commercial thermoelectric power generator 

      Hatzikraniotis, E.; Zorbas, K.; Kyratsi, Theodora; Paraskevopoulos, K. M. (Affiliation: Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceAffiliation: Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, CyprusCorrespondence Address: Hatzikraniotis, E.Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece, 2009)
      In this work, thermoelectric device was made, using a commercially available ThermoElectric Generator (TEG), in order to measure the gained power and efficiency for long- term performance. The module was subjected to ...
    • 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  

      Simulation based design of a thermoelectric energy harvesting device for aircraft applications 

      Lyras, M.; Zymaride, L.; Kyratsi, Theodora; Louca, Loucas S.; Becker, T. (American Society of Mechanical Engineers, 2017)
      Maintenance is, amongst others, a key cost driver in aircraft operation. A wireless monitoring device might be able to reduce these costs. However, the supply of energy to such system via power lines would result in ...
    • Article  

      Solid-state synthesis of Mg 2Si via short-duration ball-milling and low-temperature annealing 

      Ioannou, M.; Chrissafis, K.; Pavlidou, E.; Gascoin, F.; Kyratsi, Theodora (2013)
      In this work, a short duration ball-milling of elemental Mg and Si followed by a thermal treatment is suggested in order to synthesize magnesium silicide via solid-state reaction. The formation of magnesium silicide was ...
    • Article  

      Structural Characterization and Thermoelectric Properties of Hot-Pressed CoSi Nanocomposites 

      Ioannou, M.; Symeou, E.; Giapintzakis, John; Kyratsi, Theodora (2014)
      Fabrication of nanocomposites by introduction of SiO2 metal oxide nanoparticles into a cobalt silicide thermoelectric matrix is studied. The CoSi matrix material was prepared through solid-state synthesis, and the nano-SiO2 ...
    • Article  

      Structural features of ball-milled nanostructured K2Bi 8Se13 thermoelectric material 

      Lioutas, C. B.; Hatzikraniotis, E.; Ioannou, M.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2011)
      In this work, K2Bi8Se13 material was ball-milled in order to develop nanostructures through the modification of structural features. Structural changes during ball-milling were followed by powder X-ray diffraction measurements, ...
    • Article  

      Synthetic conditions and their doping effect on β-K2Bi8Se13 

      Kyratsi, Theodora; Kika, I.; Hatzikraniotis, E.; Paraskevopoulos, K. M.; Chrissafis, K.; Kanatzidis, M. G. (2009)
      In this work the synthetic conditions for K2Bi8Se13 and their effect on its thermoelectric properties were investigated. K2Bi8Se13 was prepared as a single phase using K2Se and Bi2Se3 as starting materials in a furnace or ...
    • 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 of Bi0.5Sb1.5Te3 thin films grown by pulsed laser deposition 

      Symeou, E.; Pervolaraki, M.; Mihailescu, C. N.; Athanasopoulos, G. I.; Papageorgiou, C.; Kyratsi, Theodora; Giapintzakis, John (2015)
      We report on the pulsed laser deposition of p-type Bi0.5Sb1.5Te3 thin films onto fused silica substrates by ablation of dense targets of Bi0.5Sb1.5Te3 with an excess of 1 wt% Te. We investigated the effect of film thickness, ...
    • Article  

      Thermoelectric properties of hot-pressed β-K2Bi 8Se13-x Sx materials 

      Kyratsi, Theodora; Ioannou, M. (2013)
      In this work, hot-pressed pellets of the K2Bi8Se 13 family of compounds were prepared for the first time. The pellet fabrication of selected members of the K2Bi8Se 13-x Sx series was studied. Sintering parameters, such as ...