# Defects modification in thermoelectric Mg<sub>2</sub>Sn (Ge) epitaxial thin films through modulation of Mg flux rate in MBE

https://mdr.nims.go.jp/datasets/9563daed-f364-4983-8a1b-e296303a81a0

## File

- [Journal of Physics Energy-Defects modification in thermoelectric Mg2Sn (Ge) epitaxial thin films through modulation of Mg flux rate in MBE.pdf](https://mdr.nims.go.jp/filesets/0b58e340-e776-4c28-98c9-7c1b73a965fe/download) ([Detail](https://mdr.nims.go.jp/filesets/0b58e340-e776-4c28-98c9-7c1b73a965fe.md))

## Id

9563daed-f364-4983-8a1b-e296303a81a0

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-11-08T15:54:37.487742Z

## Updated at

2025-11-11T03:30:20.147484Z

## Published at

2025-11-11T03:22:35.027051Z

## Doi



## First published url

https://doi.org/10.1088/2515-7655/adc489

## Date published

2025-07-31

## Recorded date published

2025-7-31

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: Defects modification in thermoelectric Mg<sub>2</sub>Sn (Ge) epitaxial thin
    films through modulation of Mg flux rate in MBE
  title_type: original
  lang: en

## Description

- description: 'Precise defect control is crucial for optimizing thermoelectric materials.
    However, thin film processes differ from bulk synthesis, necessitating distinct
    approaches to defect management. This study investigates the impact of varying
    Mg flux rates in the MBE growth of epitaxial Mg2Sn(Ge) thin films, with Mg : Sn(Ge)
    ratios from 3.9 to 9.1 while maintaining constant Sn and Ge flux rates. Our results
    indicate that while the films mainly consisted of the Mg2Sn phase due to excess
    Mg compensating evaporation at the growth temperature, the Mg flux rate significantly
    influenced film growth dynamics. X-ray diffraction analysis showed that higher
    Mg flux rates increased microstrain and decreased vertical grain sizes, suggesting
    increased planar defect density. However, the full-width half maximums (FWHMs)
    of rocking curves tend to be reduced at higher flux rates, attributed to enhanced
    in-plane grain alignment and reduction of point defect density. Positron annihilation
    experiments revealed lower vacancy-type defects at higher Mg flux rates,  aligning
    with the rocking curve measurements. The higher Mg flux rates enhanced surface
    migration and promoted larger horizontal grain growth. As these grains coalesce,
    slight misalignments between them introduce strain within the crystal lattice.
    To accommodate this strain, planar defects such as stacking faults form, as indicated
    by the X-ray pole figure measurements. Despite the higher crystal quality and
    reduction in vacancy-type defects, the total thermal conductivity of the films
    decreased with increasing Mg flux rates. This suggests that modulating Mg flux
    rates in MBE-grown Mg2Sn thin films, it is possible to achieve enhanced crystalline
    alignment and controlled formation of beneficial higher-dimensionality defects,
    which together contribute to the reduction in thermal conductivity and improve
    the film’s overall thermoelectric performance. '
  description_type: abstract
  lang: und

## Creator

- name: Kenneth Magallon Senados
  role: author
- name: Takashi Aizawa
  role: author
  orcid: https://orcid.org/0000-0003-2357-5336
  organization: National Institute for Materials Science
- name: Isao Ohkubo
  role: author
  orcid: https://orcid.org/0000-0002-4187-0112
  organization: National Institute for Materials Science
- name: Takahiro Baba
  role: author
- name: Akira Uedono
  role: author
- name: Takeaki Sakurai
  role: author
- name: Takao Mori
  role: author
  orcid: https://orcid.org/0000-0003-2682-1846
  organization: National Institute for Materials Science

## Contact agent



## Publisher

organization: IOP Publishing

## Managing organization



## Keyword

- subject: thermoelectric
  schema: not_defined

## Rights

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

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: 'Journal of Physics: Energy'
  issn: '25157655'
  volume: '7'
  issue: '3'
  article_number: '035001'

## Conference



## Related item



## Funding

- identifier: JPMXP1224NM5157
  funder_name: Advanced Research Infrastructure for Materials and Nanotechnology in
    Japan
- identifier: JPMJMI19A1
  funder_name: JST Mirai Grant

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



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## Custom property



## Fileset

- id: 0b58e340-e776-4c28-98c9-7c1b73a965fe
  filename: Journal of Physics Energy-Defects modification in thermoelectric Mg2Sn
    (Ge) epitaxial thin films through modulation of Mg flux rate in MBE.pdf
  content_type: application/pdf
  size: 1730618
  md5: e5c29ee9237e87bf929338867af8d10e

## Thumbnail

fileset_id: 0b58e340-e776-4c28-98c9-7c1b73a965fe
filename: Journal of Physics Energy-Defects modification in thermoelectric Mg2Sn (Ge)
  epitaxial thin films through modulation of Mg flux rate in MBE.pdf