Effects of heat treatment and in situ high-temperature X-ray diffraction study on the formation of ferroelectric epitaxial Y-doped HfO2 film

Takanori Mimura, Takao Shimizu, Takanori Kiguchi, Akihiro Akama, Toyohiko Konno, Yoshio Katsuya, Osami Sakata, Hiroshi Funakubo

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6 Citations (Scopus)

Abstract

The process of forming the ferroelectric orthorhombic phase was investigated for epitaxial 7% Y-doped (YHO7) films using in situ high-temperature X-ray diffraction. Epitaxial YHO7 films were grown on (111) ITO-coated (111)YSZ substrates by pulsed laser deposition at room temperature and a subsequent heat treatment process. Films deposited at room temperature were crystallized as paraelectric monoclinic phase. The monoclinic phase partially changes to tetragonal phase above 600 °C and perfectly transformed around 950 °C during heating. The change from tetragonal phase to orthorhombic phase was detected at 300 °C, corresponding to the Curie temperature under the cooling process. These results clearly suggest that the tetragonal phase was more stable at 1000 °C for YHO7 films on heating than the other phases, and the formation of this tetragonal phase - the high-temperature paraelectric phase of the ferroelectric orthorhombic phase - is key to the formation of the ferroelectric orthorhombic phase.

Original languageEnglish
Article numberSBBB09
JournalJapanese journal of applied physics
Volume58
Issue numberSB
DOIs
Publication statusPublished - 2019 Jan 1

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)

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