Spin-entropy origin and scaling behaviour of thermopower in LaBaCoO system
ORAL
Abstract
We report a detailed investigation of thermopower and magnetic properties for La$_{1-x}$Ba$_x$CoO$_3$. A large negative magnetothempower is found to scale with both magnetic field and temperature, indicating that a spin entropy contribution to thermompower. We have formulated a new and general expression to describe the thermopower from spin entropy with spin-interaction considered. Our formula can fit the scaling behavior quite well and provides a satisfactory description to the observed data. The magnetic results further consolidate our claim. This investigation suggests that spin entropy plays a substantial role in the enhanced thermopower in this cobaltite system.
*This work was supported by the MOST 973 Program of China (No.2009CB929501), the State Key Program for Basic Research of China (Grant No.2010CB923403, No.2012CB933103). T.Y. acknowledges the IMR SYNL Young Merit Scholars Research.
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