TY - JOUR
T1 - High-pressure torsion of SiO2 quartz sand
T2 - Phase transformation, optical properties, and significance in geology
AU - Wang, Qing
AU - Edalati, Kaveh
AU - Fujita, Ikuro
AU - Watanabe, Motonori
AU - Ishihara, Tatsumi
AU - Horita, Zenji
N1 - Funding Information:
This work is supported in part by AY2019 Q-PIT Support Program for Young Researchers and Doctoral Students, Kyushu University, Japan, in part by WPI-I2CNER, Japan, and in part by Grants-in-Aid for Scientific Research from MEXT, Japan (16H04539).
Funding Information:
This work is supported in part by AY2019 Q‐PIT Support Program for Young Researchers and Doctoral Students, Kyushu University, Japan, in part by WPI‐ICNER, Japan, and in part by Grants‐in‐Aid for Scientific Research from MEXT, Japan (16H04539). 2
Publisher Copyright:
© 2020 The American Ceramic Society
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Phase transformation and optical properties of silica (silicon dioxide, SiO2) quartz sand under high pressure/temperature has been of interest in geology and optical physics for many years. In this study, besides high pressure/temperature, high plastic strain is simultaneously applied to the quartz sand by high-pressure torsion (HPT) processing. The material shows oxygen vacancy formation and transformation to (a) a denser nanocrystalline quartz phase, (b) a high-temperature amorphous phase and (c) a high-pressure coesite phase. These structural and microstructural changes lead to light absorbance, electron spin resonance, photoluminscence and photocatalytic activity, while these changes are enhanced by increasing strain. This study introduces a possible pressure-temperature-strain-based mechanism for the formation of naturally observed vacancies and coesite phase in SiO2-based minerals and sands.
AB - Phase transformation and optical properties of silica (silicon dioxide, SiO2) quartz sand under high pressure/temperature has been of interest in geology and optical physics for many years. In this study, besides high pressure/temperature, high plastic strain is simultaneously applied to the quartz sand by high-pressure torsion (HPT) processing. The material shows oxygen vacancy formation and transformation to (a) a denser nanocrystalline quartz phase, (b) a high-temperature amorphous phase and (c) a high-pressure coesite phase. These structural and microstructural changes lead to light absorbance, electron spin resonance, photoluminscence and photocatalytic activity, while these changes are enhanced by increasing strain. This study introduces a possible pressure-temperature-strain-based mechanism for the formation of naturally observed vacancies and coesite phase in SiO2-based minerals and sands.
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U2 - 10.1111/jace.17362
DO - 10.1111/jace.17362
M3 - Article
AN - SCOPUS:85088373460
SN - 0002-7820
VL - 103
SP - 6594
EP - 6602
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 11
ER -