[21a-P02-1~50] 10 Spintronics and Magnetics(Poster)

▲ [21a-P02-47] Anomalous Ettingshausen effect in Fe-C alloys

〇Ren Nagasawa^1,2,3, Koichi Oyanagi³, Takamasa Hirai², Rajkumar Modak², Satoru Kobayashi³, Ken-ichi Uchida^1,2,4 (1.Tsukuba Univ., 2.NIMS, 3.Iwate Univ., 4.IMR, Tohoku Univ.)

Keywords:magneto-thermoelectric effects, spin caloritronics

In the field of spin caloritronics, developing materials that show large transverse magneto-thermoelectric effects, i.e., the anomalous Nernst effect (ANE) and its reciprocal called anomalous Ettingshausen effect (AEE), is a central research topic. Recently, researchers have particularly studied ANE and AEE in various iron-based alloys [1-3]. However, although iron-carbon alloys are widely used in industry, their transverse magneto-thermoelectric properties have not been elucidated. In this work, we report the significant enhancement of AEE in the iron-carbon alloys compared with pure iron [4].We prepared the three iron-carbon alloys with different carbon content: the ductile cast-iron, gray cast-iron, and steel. The AEE-induced temperature modulation was detected by the lock-in thermography method. Despite the small carbon concentration in the cast irons, we observed an order of magnitude larger anomalous Ettingshausen coefficient than that in pure iron [Fig. 1(a)]. The increase of the anomalous Ettingshausen coefficient results in the 540% improvement of the dimensionless figure of merit for AEE in the cast iron compared with the pure iron [Fig. 1(b)]. Our result demonstrates a potential of carbon-iron alloys as magneto-thermoelectric materials, and thus contributes to the development of spin caloritronics.