Magnetothermopower and Magnetoresistivity of RuSr2Gd1-xLaxCu2O8 (x=0, 0.1)

TL;DR

This study investigates how magnetic fields influence thermopower and resistivity in RuSr2Gd1-xLaxCu2O8, revealing that magnetic fields significantly reduce thermopower due to spin entropy effects in RuO2 layers.

Contribution

It provides new insights into the magnetic field effects on thermopower and resistivity in Ru-based cuprates, highlighting the role of RuO2 layers in conduction and thermoelectric properties.

Findings

Magnetothermopower decreases dramatically under magnetic field.

Resistivity shows only small change with magnetic field.

RuO2 layers are conducting and influence thermopower.

Abstract

We report measurements of magnetothermopower and magnetoresistivity as a function of temperature on RuSr2Gd1-xLaxCu2O8 (x = 0, 0.1). The normal-state thermopower shows a dramatic decrease after applying a magnetic field of 5 T, whereas the resistivity shows only a small change after applying the same field. Our results suggest that RuO2 layers are conducting and the magnetic field induced decrease of the overall thermopower is caused by the decrease of partial thermopower decrease associated with the spin entropy decrease of the carriers in the RuO2 layers.