Nat Mater. 2010 Nov;9(11):894-7. doi: 10.1038/nmat2856. Epub 2010 Sep 26.
Thermoelectric generation is an essential function in future energy-saving technologies. However, it has so far been an exclusive feature of electric conductors, a situation which limits its application; conduction electrons are often problematic in the thermal design of devices. Here we report electric voltage generation from heat flowing in an insulator. We reveal that, despite the absence of conduction electrons, the magnetic insulator LaY(2)Fe(5)O(12) can convert a heat flow into a spin voltage. Attached Pt films can then transform this spin voltage into an electric voltage as a result of the inverse spin Hall effect. The experimental results require us to introduce a thermally activated interface spin exchange between LaY(2)Fe(5)O(12) and Pt. Our findings extend the range of potential materials for thermoelectric applications and provide a crucial piece of information for understanding the physics of the spin Seebeck effect.
热电发电是未来节能技术的重要功能。然而，到目前为止，它一直是电导体的特有功能，这种情况限制了它的应用；在器件的热设计中，传导电子往往是一个问题。在这里，我们报告了在绝缘体中流动的热量产生的电压。我们揭示了，尽管不存在传导电子，但磁绝缘体 LaY(2)Fe(5)O(12) 可以将热流转化为自旋电压。由于逆自旋霍尔效应，附加的 Pt 薄膜随后可以将此自旋电压转换为电压。实验结果要求我们在 LaY(2)Fe(5)O(12) 和 Pt 之间引入热激活的界面自旋交换。我们的发现扩展了潜在的热电应用材料范围，并为理解自旋 Seebeck 效应的物理性质提供了关键信息。
