In the introduction of this conference contribution a review of the methods for the measurement of Seebeck coefficient (S), electrical conductivity (s) and thermal conductivity (k) of thermoelectric samples to determine their figure of merit ZR in accordance to the equation ZT = sS**2T/k is given. On the background of this information a concept and construction of a Z-meter we made is presented, which enable us to measure all three parameters simultaneously up to temperature 500oC and to determine a figure of merit ZT of the samples. The measurement is fully automatic and performed in a vacuum of about 10-3Pa on samples with diameter up to 12 mm and height of about 10 mm.
F.13 Development of new production methods and tools or processes
COBISS.SI-ID: 27103527In this work the results of studying the influence of organic vehicle and amount of solids load (varistor powder mixture) on rheological properties of ink for screen printing are presented, which enabled us to prepare an ink with high solids load of 70% and good printing characteristics. The ink enables us to prepare homogeneous and dense varistor layers after firing at 900oC for 15 minutes.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 27103783Sintering, grain growth and microstructure development in ZnO-based varistor ceramics doped with MoO3, sintered at temperatures below 1000oC, were studied. Doping with MoO3 is interesting because MoO3 and Bi2O3 form phases with high ionic conductivity and stability on cooling to quite low temperatures, which could positively affect varistor nature of the grain boundaries. In regard to the amount of added MoO3, the varistor ceramics with useful breakdown voltages in the range from 400 to 540V/mm and nonlinearity coefficient alfa about 30 were obtained after sintering at 920oC.
F.10 Improvements to an existing technological process or technology
COBISS.SI-ID: 27456551