Enhancement of anomalous Nernst effects in metallic multilayers free from proximity-induced magnetism

近接効果による磁性無しでの金属多層幕中の異常ネルンスト効果の増進

内田 健一*; 吉川 貴史*; 関 剛斎*; 小宅 教文*; 塩見 淳一郎*; Qiu, Z.*; 高梨 弘毅*; 齊藤 英治

Uchida, Kenichi*; Kikkawa, Takashi*; Seki, Takeshi*; Oyake, Takafumi*; Shiomi, Junichiro*; Qiu, Z.*; Takanashi, Koki*; Saito, Eiji

The anomalous Nernst effect (ANE) has been investigated in alternately stacked multilayer films comprising paramagnetic and ferromagnetic metals. We found that the ANE is enhanced by increasing the number of the paramagnet/ferromagnet interfaces and keeping the total thickness of the films constant, and that the enhancement appears even in the absence of magnetic proximity effects; similar behavior was observed not only in Pt/Fe multilayers but also in Au/Fe and Cu/Fe multilayers free from proximity ferromagnetism. This universal enhancement of the ANE in metallic multilayers suggests the presence of unconventional interface-induced thermoelectric conversion in the Fe films attached to the paramagnets.