Optical Properties of Nanocrystalline Monoclinic Y2O3 Stabilized by Grain Size and Plastic Strain Effects via High-Pressure Torsion

Hadi Razavi-Khosroshahi, Kaveh Edalati, Hoda Emami, Etsuo Akiba, Zenji Horita, Masayoshi Fuji

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Yttrium oxide (yttria) with monoclinic structure exhibits unique optical properties; however, the monoclinic phase is thermodynamically stable only at pressures higher than ∼16 GPa. In this study, the effect of grain size and plastic strain on the stability of monoclinic phase is investigated by a high-pressure torsion (HPT) method. A cubic-to-monoclinic phase transition occurs at 6 GPa, which is ∼10 GPa below the theoretical transition pressure. Microstructure analysis shows that monoclinic phase forms in nanograins smaller than ∼22 nm and its fraction increases with plastic strain, while larger grains have a cubic structure. The band gap decreases and the photoluminescence features change from electric dipole to mainly magnetic dipole without significant decrease in the photoluminescence intensity after formation of the monoclinic phase. It is also suggested that monoclinic phase formation is due to the enhancement of effective internal pressure in nanograins.

Original languageEnglish
Pages (from-to)2576-2580
Number of pages5
JournalInorganic Chemistry
Volume56
Issue number5
DOIs
Publication statusPublished - Mar 6 2017

Fingerprint

Torsional stress
torsion
Plastic deformation
plastics
Optical properties
grain size
photoluminescence
yttrium oxides
optical properties
transition pressure
internal pressure
magnetic dipoles
electric dipoles
Photoluminescence
microstructure
augmentation
Energy gap
Phase transitions
Microstructure
yttria

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this

Optical Properties of Nanocrystalline Monoclinic Y2O3 Stabilized by Grain Size and Plastic Strain Effects via High-Pressure Torsion. / Razavi-Khosroshahi, Hadi; Edalati, Kaveh; Emami, Hoda; Akiba, Etsuo; Horita, Zenji; Fuji, Masayoshi.

In: Inorganic Chemistry, Vol. 56, No. 5, 06.03.2017, p. 2576-2580.

Research output: Contribution to journalArticle

Razavi-Khosroshahi, Hadi ; Edalati, Kaveh ; Emami, Hoda ; Akiba, Etsuo ; Horita, Zenji ; Fuji, Masayoshi. / Optical Properties of Nanocrystalline Monoclinic Y2O3 Stabilized by Grain Size and Plastic Strain Effects via High-Pressure Torsion. In: Inorganic Chemistry. 2017 ; Vol. 56, No. 5. pp. 2576-2580.
@article{ca7b71811daf41029716d4ba3a111c73,
title = "Optical Properties of Nanocrystalline Monoclinic Y2O3 Stabilized by Grain Size and Plastic Strain Effects via High-Pressure Torsion",
abstract = "Yttrium oxide (yttria) with monoclinic structure exhibits unique optical properties; however, the monoclinic phase is thermodynamically stable only at pressures higher than ∼16 GPa. In this study, the effect of grain size and plastic strain on the stability of monoclinic phase is investigated by a high-pressure torsion (HPT) method. A cubic-to-monoclinic phase transition occurs at 6 GPa, which is ∼10 GPa below the theoretical transition pressure. Microstructure analysis shows that monoclinic phase forms in nanograins smaller than ∼22 nm and its fraction increases with plastic strain, while larger grains have a cubic structure. The band gap decreases and the photoluminescence features change from electric dipole to mainly magnetic dipole without significant decrease in the photoluminescence intensity after formation of the monoclinic phase. It is also suggested that monoclinic phase formation is due to the enhancement of effective internal pressure in nanograins.",
author = "Hadi Razavi-Khosroshahi and Kaveh Edalati and Hoda Emami and Etsuo Akiba and Zenji Horita and Masayoshi Fuji",
year = "2017",
month = "3",
day = "6",
doi = "10.1021/acs.inorgchem.6b02725",
language = "English",
volume = "56",
pages = "2576--2580",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "5",

}

TY - JOUR

T1 - Optical Properties of Nanocrystalline Monoclinic Y2O3 Stabilized by Grain Size and Plastic Strain Effects via High-Pressure Torsion

AU - Razavi-Khosroshahi, Hadi

AU - Edalati, Kaveh

AU - Emami, Hoda

AU - Akiba, Etsuo

AU - Horita, Zenji

AU - Fuji, Masayoshi

PY - 2017/3/6

Y1 - 2017/3/6

N2 - Yttrium oxide (yttria) with monoclinic structure exhibits unique optical properties; however, the monoclinic phase is thermodynamically stable only at pressures higher than ∼16 GPa. In this study, the effect of grain size and plastic strain on the stability of monoclinic phase is investigated by a high-pressure torsion (HPT) method. A cubic-to-monoclinic phase transition occurs at 6 GPa, which is ∼10 GPa below the theoretical transition pressure. Microstructure analysis shows that monoclinic phase forms in nanograins smaller than ∼22 nm and its fraction increases with plastic strain, while larger grains have a cubic structure. The band gap decreases and the photoluminescence features change from electric dipole to mainly magnetic dipole without significant decrease in the photoluminescence intensity after formation of the monoclinic phase. It is also suggested that monoclinic phase formation is due to the enhancement of effective internal pressure in nanograins.

AB - Yttrium oxide (yttria) with monoclinic structure exhibits unique optical properties; however, the monoclinic phase is thermodynamically stable only at pressures higher than ∼16 GPa. In this study, the effect of grain size and plastic strain on the stability of monoclinic phase is investigated by a high-pressure torsion (HPT) method. A cubic-to-monoclinic phase transition occurs at 6 GPa, which is ∼10 GPa below the theoretical transition pressure. Microstructure analysis shows that monoclinic phase forms in nanograins smaller than ∼22 nm and its fraction increases with plastic strain, while larger grains have a cubic structure. The band gap decreases and the photoluminescence features change from electric dipole to mainly magnetic dipole without significant decrease in the photoluminescence intensity after formation of the monoclinic phase. It is also suggested that monoclinic phase formation is due to the enhancement of effective internal pressure in nanograins.

UR - http://www.scopus.com/inward/record.url?scp=85014788205&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85014788205&partnerID=8YFLogxK

U2 - 10.1021/acs.inorgchem.6b02725

DO - 10.1021/acs.inorgchem.6b02725

M3 - Article

AN - SCOPUS:85014788205

VL - 56

SP - 2576

EP - 2580

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 5

ER -