Structure of crystallized particles in sputterdeposited amorphous germanium films

Masayuki Okugawa, Ryusuke Nakamura, Akihiko Hirata, Manabu Ishimaru, Hidehiro Yasuda, Hiroshi Numakura

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Pristine thin films of amorphous Ge prepared by sputtering are unstable and form coarse crystalline particles of 100 nm in size upon crystallization by electron irradiation. These crystalline particles exhibit unusual diffraction patterns that cannot be understood from the diamond cubic structure. The structure has previously been assumed to be a metastable hexagonal form. In the present work, the structure of the coarse crystalline particles has been analysed in detail by transmission electron microscopy, considering the possibility that those diffraction patterns might occur with the diamond cubic structure if the particle consists of thin twin layers. By high-resolution lattice imaging the particles have been shown to be of the diamond cubic structure containing a high density of twins and stacking faults parallel to {111}. With such defects, diffraction patterns can be complex because of the following effects: superposition of two or more diffraction patterns of the same structure but of different orientations, double diffraction through twin crystals, and streaks parallel to the thin crystal which give rise to extra diffraction spots. It is found that diffraction patterns taken from various orientations can be explained in terms of these effects.

Original languageEnglish
Pages (from-to)1467-1473
Number of pages7
JournalJournal of Applied Crystallography
Volume51
Issue number5
DOIs
Publication statusPublished - 2018 Oct 1

Fingerprint

Germanium
Diamond
Diffraction patterns
Crystalline materials
Crystallization
Transmission Electron Microscopy
Diffraction
Crystals
Electron irradiation
Electrons
Stacking faults
Crystal orientation
Sputtering
Transmission electron microscopy
Imaging techniques
Thin films
Defects

Keywords

  • Crystallized Ge thin films
  • Streaking effects
  • Twinning

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Structure of crystallized particles in sputterdeposited amorphous germanium films. / Okugawa, Masayuki; Nakamura, Ryusuke; Hirata, Akihiko; Ishimaru, Manabu; Yasuda, Hidehiro; Numakura, Hiroshi.

In: Journal of Applied Crystallography, Vol. 51, No. 5, 01.10.2018, p. 1467-1473.

Research output: Contribution to journalArticle

Okugawa, Masayuki ; Nakamura, Ryusuke ; Hirata, Akihiko ; Ishimaru, Manabu ; Yasuda, Hidehiro ; Numakura, Hiroshi. / Structure of crystallized particles in sputterdeposited amorphous germanium films. In: Journal of Applied Crystallography. 2018 ; Vol. 51, No. 5. pp. 1467-1473.
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