Preparation of Ruddlesden-Popper Type Ca_n+1(Mn_1-xV_x)_nO_3n+1 (n=2) Powders and Thermoelectric Conversion Properties of their Sintered Compacts

Abstract

Ruddlesden-Popper type compounds, being presented as (ABO₃)_n-AO or A_n+1B_nO_3n+1 (n=1, 2, 3…∞), have a layer structure where perovskite layer ABO₃ and rock salt type layer AO are alternately in place; Ca_n+1(Mn_1-xV_x)_nO_3n+1 (0≤x≤1) belongs also to this compound. As CaO layer shows low thermal conductivity whereas CaMnO₃ layer reveals high electrical conductivity and high Seebeck coefficient, therefore, Ca_n+1(Mn_1-xV_x)_nO_3n+1 seems to become a promising module as a thermoelectric conversion material. However, there was no report concerning about the thermoelectric conversion characteristic of this compound. In this study we have investigated electrical conductivity, Seebeck coefficient, and thermal conductivity of Ca_n+1(Mn_1-xV_x)_nO_3n+1 and discussed about the possibility of the application as thermoelectric conversion elements from dimensionless performance index ZT.