Nav: Home

Observation of anisotropic magneto-Peltier effect

June 18, 2018

For the first time in the world, NIMS and Tohoku University jointly observed an anisotropic magneto-Peltier effect--a thermoelectric conversion phenomenon in which simple redirection of a charge current in a magnetic material induces heating and cooling. Thermoelectric heating and cooling are conventionally achieved by applying a charge current to a junction between two different electrical conductors. In this research, we demonstrated a novel thermal control function using a single magnetic material without relying on a junction structure. Although the anisotropic magneto-Peltier effect is one of the fundamental thermoelectric conversion phenomena, it remained to be observed. We hope that this report will stimulate further advances in basic and applied research on thermoelectric conversion.

Conversion between charge and heat currents can be achieved in metals and semiconductors by means of the thermoelectric effect. A well-known example of the conversion is the Peltier effect, whereby a conductor can be heated or cooled by applying a charge current. Although the Peltier effect was discovered almost 200 years ago, global research activities on this subject remain active today in an effort to increase the thermoelectric conversion efficiency in electronic devices and apply this phenomenon to a wider range of technologies (e.g., development of more energy-efficient computers).

The NIMS-led research team used a thermal measurement technique called lock-in thermography to make systematic measurements of temperature changes in a magnetic material while a charge current was applied. As a result, we observed changes in the Peltier coefficient in relation to the angle between the direction of the charge current and the direction of the magnetization in the magnetic material. It has been previously observed that the Seebeck effect--a phenomenon in which a temperature difference between a conductor produces a charge current--changes in relation to the direction of magnetization; this is called the anisotropic magneto-Seebeck effect. However, the anisotropic magneto-Peltier effect, which is the reciprocal of the anisotropic magneto Seebeck effect, had not been observed before this research.

Application of the anisotropic magneto-Peltier effect may enable thermoelectric temperature control of a magnetic material by simply redirecting a charge current in the material and creating a non-uniform magnetization configuration within it, rather than forming a junction between two different electrical conductors. In future studies, we will attempt to identify and develop magnetic materials that exhibit large anisotropic magneto-Peltier effects and apply them to the development of thermal management technologies that make electronic devices energy-efficient.
-end-
This research project was carried out by Ken-ichi Uchida (Group Leader, Spin Caloritronics Group, Research Center for Magnetic and Spintronic Materials, NIMS), Ryo Iguchi (Researcher, Spin Caloritronics Group, Research Center for Magnetic and Spintronic Materials, NIMS), Shunsuke Daimon (Graduate Student, Institute for Materials Research and Advanced Institute for Materials Research, Tohoku University; currently Assistant Professor of The University of Tokyo) and Eiji Saitoh (Professor, Institute for Materials Research and Advanced Institute for Materials Research, Tohoku University; currently Professor of the University of Tokyo).

This project was supported mainly by the JST Strategic Basic Research Program CREST (JPMJCR17I1) and the JSPS Grant-in-Aid for Scientific Research (A) (JP15H02012).

This research was published in the online version of the British scientific journal Nature at May 22, 2018, Japan Time.

Contacts

(Regarding this research)
Ken-ichi Uchida
Group Leader, Spin Caloritronics Group
Research Center for Magnetic and Spintronic Materials
National Institute for Materials Science
Tel: +81-29-859-2062
Fax: +81-29-859-2701
URL: http://www.nims.go.jp/mmu/scg/
Email: UCHIDA.Kenichi@nims.go.jp

National Institute for Materials Science, Japan

Related Research Articles:


Related Research Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Moving Forward
When the life you've built slips out of your grasp, you're often told it's best to move on. But is that true? Instead of forgetting the past, TED speakers describe how we can move forward with it. Guests include writers Nora McInerny and Suleika Jaouad, and human rights advocate Lindy Lou Isonhood.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...