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 language | English |
|---|---|
| Pages (from-to) | 2576-2580 |
| Number of pages | 5 |
| Journal | Inorganic Chemistry |
| Volume | 56 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Mar 6 2017 |
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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 journal › Article
}
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.
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U2 - 10.1021/acs.inorgchem.6b02725
DO - 10.1021/acs.inorgchem.6b02725
M3 - Article
C2 - 28186732
AN - SCOPUS:85014788205
VL - 56
SP - 2576
EP - 2580
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 5
ER -