Enhancement of mechanical hardness in SnOxNy with a dense high-pressure cubic phase of SnO2

Hyo Jin Gwon, Na Ri Kang, Yunju Lee, Sung Ok Won, Hye Jung Chang, Ji Won Choi, Chong Yun Kang, Seong Keun Kim, Beomjin Kwon, Sahn Nahm, Ju Young Kim, Jin Sang Kim, Seung Hyub Baek

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


Controlling crystalline phases in polymorphic materials is critical not only for the fundamental understanding of the physics of phase formation but also for the technological application of forbidden, but potentially useful physical properties of the nominally unstable phases. Here, using tin oxide (SnO2) as a model system, we demonstrate a new way to enhance the mechanical hardness of an oxide by stabilizing a high-pressure dense phase through nitrogen integration in the oxide. Pristine SnO2 has a tetragonal structure at the ambient pressure, and undergoes phase transitions to orthorhombic and cubic phases with increasing pressure. Leveraging the enhanced reactivity of nitrogen in plasma, we are able to synthesize tin oxynitride (SnON) thin films with a cubic phase same as the high-pressure phase of SnO2. Such nitrogen-stabilized cubic SnON films exhibit a mechanical hardness of ∼23 ± 4 GPa, significantly higher than even the nitride counterpart (Sn3N4) as the result of the shortened atomic distance of the denser, high-pressure cubic phase. Moreover, SnON has a heavily doped, n-type semiconducting property with a controllable optical bandgap. Our work will provide new opportunities to search for and to utilize beneficial, but hidden physical properties that exist in a particular phase stable only at extreme conditions.

Original languageEnglish
Pages (from-to)7051-7057
Number of pages7
JournalChemistry of Materials
Issue number19
Publication statusPublished - 2016 Oct 11

Bibliographical note

Funding Information:
The authors gratefully acknowledge the financial support of the Korea Institute of Science and Technology (KIST) through 2E26370.

Publisher Copyright:
© 2016 American Chemical Society.

ASJC Scopus subject areas

  • General Chemistry
  • General Chemical Engineering
  • Materials Chemistry


Dive into the research topics of 'Enhancement of mechanical hardness in SnOxNy with a dense high-pressure cubic phase of SnO2'. Together they form a unique fingerprint.

Cite this