Effect of Na Addition on Electric Properties of Ca₂Si Sintered Compacts

Preparation of Ca-Si Films on (001) Al2O3 Substrates by an RF Magnetron Sputtering Method and Their Electrical Properties

“…5 indicate the reported data for the Ca-Si system. [4][5][6]12 The present and reported results basically almost agree except for the reported lower conductivity of Ca 5 Si 3 . As mentioned above, a difference in the electrical conductivity by two orders of magnitude was reported for Ca 5 Si 3 bulks synthesized by different methods.…”

“…Some compounds have been reported in the Ca-Mg-Si system, which is a ternary system of Mg-Si with Ca. 3 In addition, Ca 2 Si, Ca 5 Si 3 , and CaMgSi phases show p-type conduction, [4][5][6][7] suggesting that other p-type thermoelectric compounds can be used together with n-type Mg 2 Si. Regardless of these studies, the ternary system of Ca-Si is not well understood.…”

“…6 Moreover, the electrical conductivities of Ca 5 Si 3 synthesized by two different methods differing by two orders of magnitude. [4][5][6] To elucidate the electrical properties of these compounds, a systematic investigation using highdensity samples prepared by the same method must be carried out. We have previously reported the electrical conductivity and the Seebeck coefficient of Mg 2 Si films prepared on (001) Al 2 O 3 substrates via a sputtering method.…”

Reactive Spark Plasma Sintering and Thermoelectric Properties of Zintl Semiconducting Ca14Si19 Compound

“…Growth of thin films has been performed for applications such as light-emitting diodes in the near-infrared range [32]. Thermoelectric and electrical transport experiments on orthorhombic Ca 2 Si [43,44] showed that it is p-type and that the electrical conductivity (σ) is too weak, even after doping with Na, and that the energy activation found is much smaller than the energy bandgap found from the optical experiments [32]. Concerning Ca 5 Si 3 , there are several contradicting results.…”