Observations of Co4+ in a higher spin state and the increase in the Seebeck coefficient of thermoelectric Ca3Co4O9.
نویسندگان
چکیده
Ca3Co4O9 has a unique structure that leads to exceptionally high thermoelectric transport. Here we report the achievement of a 27% increase in the room-temperature in-plane Seebeck coefficient of Ca3Co4O9 thin films. We combine aberration-corrected Z-contrast imaging, atomic-column resolved electron energy-loss spectroscopy, and density-functional calculations to show that the increase is caused by stacking faults with Co4+-ions in a higher spin state compared to that of bulk Ca3Co4O9. The higher Seebeck coefficient makes the Ca3Co4O9 system suitable for many high temperature waste-heat-recovery applications.
منابع مشابه
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ورودعنوان ژورنال:
- Physical review letters
دوره 108 19 شماره
صفحات -
تاریخ انتشار 2012