DC electrical resistivity (r) and thermoelectric power (TEP) of La0.7xBixSr0.3MnOy (x=0, 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3 at%) manganites have been studied. The resistivity of the samples shows a metal–semiconductor (insulator) transition for xX0.2. For x=0.25 and 0.3 at%, the compounds exhibit semiconducting behavior down to T=83 K. The TEP for xp0.2 at% is of positive sign above the ...
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