High-temperature strength of bulk single crystals of III-V nitrides

I. Yonenaga

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


A Vickers indentation method was used to determine the hardness of AlN and GaN, grown by the hydride vapor phase epitaxy technique, in the temperature range 20-1400°C. At room temperature, the hardnesses of GaN and AlN are 10.2 and 17.7 GPa, respectively. The hardness of GaN and AlN shows a gradual decrease from RT and then a step decrease from around 1000°C. AlN is harder than GaN but softer than SiC. The steep decrease of the hardness means the beginning of macroscopic dislocation motion and plastic deformation. The mechanical strength of bulk single-crystal GaN is investigated at elevated temperatures directly by means of compressive deformation. The yield stress of GaN in the temperature range 900-1000°C is around 100-200 MPa, i.e., similar to that of 6H-SiC and much higher than those of Si, Ge, GaAs.

Original languageEnglish
Pages (from-to)279-281
Number of pages3
JournalJournal of Materials Science: Materials in Electronics
Issue number5-7
Publication statusPublished - 2003 May

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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