# Phase-selective sputter epitaxy of                    <i>δ</i>                    -NbN,                    <i>γ</i>                    -Nb4N3, and                    <i>β</i>                    -Nb2N on atomically flat AlN

https://mdr.nims.go.jp/datasets/bae38148-98af-4c66-87e2-73081c0dd353

## File

- [出版社版OA.pdf](https://mdr.nims.go.jp/filesets/2f19d323-4df3-4114-92ce-e1ccdddc675a/download) ([Detail](https://mdr.nims.go.jp/filesets/2f19d323-4df3-4114-92ce-e1ccdddc675a.md))

## Id

bae38148-98af-4c66-87e2-73081c0dd353

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2026-06-16T00:30:26.663830Z

## Updated at

2026-06-16T02:26:56.341302Z

## Published at

2026-06-16T03:26:20.825748Z

## Doi



## First published url

https://doi.org/10.1063/5.0311297

## Date published

2026-05-14

## Recorded date published

2026-5-14

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: Phase-selective sputter epitaxy of                    <i>δ</i>                    -NbN,                    <i>γ</i>                    -Nb4N3,
    and                    <i>β</i>                    -Nb2N on atomically flat AlN
  title_type: original
  lang: en

## Description

- description: 'We report the phase-selective epitaxy of δ-NbN, γ-Nb4N3, and β-Nb2N
    thin films on AlN/sapphire templates by sputtering. Structural analysis revealed
    coherent epitaxial growth with sharp x-ray diffraction fringes, phase-dependent
    surface reconstructions observed by reflection high-energy electron diffraction,
    and atomically flat morphologies with a root-mean-square roughness below 1 nm.
    Reciprocal space mapping confirmed lattice coherence, while rocking curves exhibited
    narrow full width at half maximum values for δ-NbN and β-Nb2N, with slightly broader
    peaks for γ-Nb4N3. Transport measurements showed distinct superconducting behaviors:
    δ-NbN displayed an insulating-like resistivity upturn with Tc ∼ 12 K, γ-Nb4N3
    exhibited metallic behavior with Tc ∼ 10 K, and β-Nb2N showed metallic conduction
    with Tc as low as 0.4 K, indicating high phase purity. The retention of high Tc
    values in ultrathin films underscores the robustness of sputter-grown NbNx on
    AlN. These results define the growth windows for multiple NbNx phases and establish
    AlN as a versatile platform for integrating superconductivity with III-nitride
    semiconductors in future hybrid devices.'
  description_type: abstract
  lang: und

## Creator

- name: Yuki Kato
  role: author
- name: Koryo Masuzawa
  role: author
- name: Takayuki Harada
  role: author
  orcid: https://orcid.org/0000-0002-8657-2258
  organization: National Institute for Materials Science
- name: Hideto Miyake
  role: author
- name: Atsushi Kobayashi
  role: author

## Contact agent



## Publisher

organization: National Institute for Materials Science
ror: https://ror.org/

## Managing organization



## Keyword

- subject: Thin films
  schema: not_defined
- subject: Superconductivity
  schema: not_defined
- subject: Nitrides
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by/4.0/
  date_licensed: 2026-05-09

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: Journal of Applied Physics
  issn: '00218979'
  volume: '139'
  issue: '18'
  article_number: '185301'

## Conference



## Related item



## Funding

- identifier: JP23KK0094
  funder_name: Japan Society for the Promotion of Science London
- identifier: JP25K22019 and JP 25K01680
  funder_name: Japan Society for the Promotion of Science London

## 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



## Software



## Custom property



## Fileset

- id: 2f19d323-4df3-4114-92ce-e1ccdddc675a
  filename: 出版社版OA.pdf
  content_type: application/pdf
  size: 1914433
  md5: 68284c0f7492d3ebfe176fa237be83fc

## Thumbnail

fileset_id: 2f19d323-4df3-4114-92ce-e1ccdddc675a
filename: 出版社版OA.pdf