# Simultaneous achievement of large anomalous Nernst effect and reduced thermal conductivity in sintered polycrystalline topological Heusler ferromagnets

https://mdr.nims.go.jp/datasets/b934ebcf-4095-45c9-bde0-9d4cbb4e5147

## File

- [Oyanagi_manuscript_published.pdf](https://mdr.nims.go.jp/filesets/b1b1e980-e95c-4ba8-b76c-d62bbc7bbbf7/download) ([Detail](https://mdr.nims.go.jp/filesets/b1b1e980-e95c-4ba8-b76c-d62bbc7bbbf7.md))

## Id

b934ebcf-4095-45c9-bde0-9d4cbb4e5147

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-06-23T16:12:34.487368Z

## Updated at

2025-06-24T03:30:20.902979Z

## Published at

2025-06-24T03:21:27.677592Z

## Doi



## First published url

https://doi.org/10.1016/j.actamat.2025.121239

## Date published

2025-06-09

## Recorded date published

2025-9

## Resource type

journal_article

## Manuscript type

accepted_manuscript

## Collection



## Title

- title: Simultaneous achievement of large anomalous Nernst effect and reduced thermal
    conductivity in sintered polycrystalline topological Heusler ferromagnets
  title_type: original
  lang: en

## Description

- description: Thermoelectric conversion based on the anomalous Nernst effect (ANE)
    is promising for energy harvesting as its transverse geometry enables the design
    of large-scale thermoelectric devices with simple structures. While topological
    ferromagnets, typically single crystals, exhibit large ANE, achieving high conversion
    performance remains challenging because it also requires high electric conductivity
    and low thermal conductivity. Here, we report enhanced transverse thermoelectric
    conversion performance in polycrystalline topological ferromagnet Co2MnGa (CMG)
    prepared by spark plasma sintering. Optimization of the sintering conditions for
    CMG leads to the anomalous Nernst coefficient of 7.5 µV K-1 at room temperature,
    comparable to the highest value reported for the single crystals, and simultaneously
    reduces its thermal conductivity by 34 % compared to that of the single crystals
    without affecting the electric conductivity. Owing to the transport properties
    that overcome conventional trade-off relations, our optimized CMG slab shows the
    record-high value of the dimensionless figure of merit for ANE at room temperature.
    Detailed nano/microstructure characterizations and first-principles phonon calculations
    clarify the unconventional dependence of the transport properties on the degree
    of crystalline ordering and morphology of crystal-domain boundaries. The results
    reveal the potential of polycrystalline topological materials for transverse thermoelectric
    applications and suggest alternative strategies to nanostructuring for enhancing
    thermoelectric performance.
  description_type: abstract
  lang: und

## Creator

- name: Koichi Oyanagi
  role: author
  orcid: https://orcid.org/0000-0001-8784-078X
- name: Hossein Sepehri-Amin
  role: author
  orcid: https://orcid.org/0000-0002-7856-7897
- name: Kenta Takamori
  role: author
- name: Terumasa Tadano
  role: author
  orcid: https://orcid.org/0000-0002-8132-2161
- name: Takumi Imamura
  role: author
- name: Ren Nagasawa
  role: author
- name: Krishnan Mahalingam
  role: author
  orcid: https://orcid.org/0000-0002-0075-3657
- name: Takamasa Hirai
  role: author
  orcid: https://orcid.org/0000-0002-5577-8018
- name: Fuyuki Ando
  role: author
  orcid: https://orcid.org/0009-0003-7789-8170
- name: Yuya Sakuraba
  role: author
  orcid: https://orcid.org/0000-0003-4618-9550
- name: Satoru Kobayashi
  role: author
  orcid: https://orcid.org/0000-0002-3545-2977
- name: Ken-ichi Uchida
  role: author
  orcid: https://orcid.org/0000-0001-7680-3051

## Contact agent



## Publisher

organization: Elsevier BV

## Managing organization



## Keyword

- subject: Anomalous Nernst effect
  schema: not_defined
- subject: Heusler alloy
  schema: not_defined
- subject: Microstructure characterization
  schema: not_defined
- subject: Thermoelectric materials
  schema: not_defined
- subject: First-principles phonon calculation
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by/4.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: Acta Materialia
  issn: '13596454'
  volume: '296'
  article_number: '121239'

## Conference



## Related item



## Funding

- identifier: JPMJCR17I1
  funder_name: Japan Science and Technology Agency
- identifier: JPMJER2201
  funder_name: Japan Science and Technology Agency
- funder_name: National Institute for Materials Science
- funder_name: NEC Corporation
- identifier: 21K14519
  funder_name: Japan Society for the Promotion of Science
- identifier: 22H04965
  funder_name: Japan Society for the Promotion of Science

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## Fileset

- id: b1b1e980-e95c-4ba8-b76c-d62bbc7bbbf7
  filename: Oyanagi_manuscript_published.pdf
  content_type: application/pdf
  size: 2782618
  md5: 979ad43fb573722bba929261d52cb8f6

## Thumbnail

fileset_id: b1b1e980-e95c-4ba8-b76c-d62bbc7bbbf7
filename: Oyanagi_manuscript_published.pdf