Strain-induced switching of heat current direction generated by magneto-thermoelectric effects

• Published in: Scientific reports Vol. 9; no. 1; pp. 13197 - 7
• Main Authors: Ota, Shinya, Uchida, Ken-ichi, Iguchi, Ryo, Thach, Pham Van, Awano, Hiroyuki, Chiba, Daichi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.09.2019; Nature Publishing Group
• Subjects: 142/126; 639/301/119/1001; 639/766/25; Electronic equipment; Fourier analysis; Heat; Humanities and Social Sciences; Information processing; Magnetic fields; Magnetic thin films; Materials science; multidisciplinary; Science; Science (multidisciplinary); Thermography
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-49567-2

Since the charge current plays a major role in information processing and Joule heating is inevitable in electronic devices, thermal management, i.e., designing heat flows, is required. Here, we report that strain application can change a direction of a heat current generated by magneto-thermoelectric effects. For demonstration, we used metallic magnets in a thin-film form, wherein the anomalous Ettingshausen effect mainly determines the direction of the heat flow. Strain application can alter the magnetization direction owing to the magnetoelastic effect. As a result, the heat current, which is in the direction of the cross product of the charge current and the magnetization vector, can be switched or rotated simply by applying a tensile strain to the metallic magnets. We demonstrate 180° switching and 90° rotation of the heat currents in an in-plane magnetized Ni sample on a rigid sapphire substrate and a perpendicularly magnetized TbFeCo film on a flexible substrate, respectively. An active thermography technique was used to capture the strain-induced change in the heat current direction. The method presented here provides a novel method for controlling thermal energy in electronic devices.