Anomalous Nernst effect inLa0.88MnO3

Nernst coefficient measurements of ${\mathrm{La}}_{0.88}{\mathrm{MnO}}_3$ ($T_c\sim 265$ K) are reported as a function of temperature (100–320 K) in moderate applied magnetic fields $(0.38<H<\mathrm{}1.8\mathrm{}$ T). For $T>\mathrm{}{T}_c,$ our data can be accounted for by the transport behavior of small polarons. We find the semiconductor to metal transition is dominated by an increase in the hole density. For $T<~T_c,$ an anomalous suppression of the Nernst coefficient was observed when the field increased from 0.38 to 1.8 T. The giant magnetoresistance effect is attributed to a field increased mobility of the charge carriers.