Polycrystalline specimens of Pr
1-xSr
xFeO
3 (0.1 ≤
x ≤ 0.7) were synthesized using a solid state reaction method. All samples had a typical perovskite structure, where the orthorhombic (
Pbnm) phase was dominant at
x≦0.5 and the rhombohedral (
R-3
c) phase was dominant at
x≧0.6. Since the B site is in the mixed valence state of Fe
3+/ Fe
4+ and the spin quantum number is in the range of 0.86 ≤
s ≤ 1.15, it is expected that Fe
3+ is in the spin state of low spin (LS) Fe
3+ or intermediate spin (IS) Fe
3+ and Fe
4+ is in the spin sate of LS Fe
4+. As x increases, the ratio of IS Fe
3+ decreases compared to that of LS Fe
3+ at
x≧0.3, so that the P-type Seebeck coefficient is maintained up to
x = 0.5. Although
ZT = 0.002 @ 850 K of
x=0.7 which shows the maximum N-type thermoelectric characteristic is about 9% of
ZT = 0.024 @ 850 K of
x = 0.1 which shows the maximum P-type thermoelectric characteristic, both are the results of relatively high Seebeck coefficient, low electrical resistivity, and low thermal conductivity. Therefore, we strongly suggest that there is a possibility of application of PN elements which compose of the perovskite type oxides.
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