TY - JOUR
T1 - Degree of Permanent Densification in Oxide Glasses upon Extreme Compression up to 24 GPa at Room Temperature
AU - Lee, Sung Keun
AU - Mun, Kwan Young
AU - Kim, Yong Hyun
AU - Lhee, Juho
AU - Okuchi, Takuo
AU - Lin, Jung Fu
PY - 2020/4/16
Y1 - 2020/4/16
N2 - During the decompression of plastically deformed glasses at room temperature, some aspects of irreversible densification may be preserved. This densification has been primarily attributed to topological changes in glass networks. The changes in short-range structures like cation coordination numbers are often assumed to be relaxed upon decompression. Here the NMR results for aluminosilicate glass upon permanent densification up to 24 GPa reveal noticeable changes in the Al coordination number under pressure conditions as low as ∼6 GPa. A drastic increase in the highly coordinated Al fraction is evident over only a relatively narrow pressure range of up to ∼12 GPa, above which the coordination change becomes negligible up to 24 GPa. In contrast, Si coordination environments do not change, highlighting preferential coordination transformation during deformation. The observed trend in the coordination environment shows a remarkable similarity to the pressure-induced changes in the residual glass density, yielding a predictive relationship between the irreversible densification and the detailed structures under extreme compression. The results open a way to access the nature of plastic deformation in complex glasses at room temperature.
AB - During the decompression of plastically deformed glasses at room temperature, some aspects of irreversible densification may be preserved. This densification has been primarily attributed to topological changes in glass networks. The changes in short-range structures like cation coordination numbers are often assumed to be relaxed upon decompression. Here the NMR results for aluminosilicate glass upon permanent densification up to 24 GPa reveal noticeable changes in the Al coordination number under pressure conditions as low as ∼6 GPa. A drastic increase in the highly coordinated Al fraction is evident over only a relatively narrow pressure range of up to ∼12 GPa, above which the coordination change becomes negligible up to 24 GPa. In contrast, Si coordination environments do not change, highlighting preferential coordination transformation during deformation. The observed trend in the coordination environment shows a remarkable similarity to the pressure-induced changes in the residual glass density, yielding a predictive relationship between the irreversible densification and the detailed structures under extreme compression. The results open a way to access the nature of plastic deformation in complex glasses at room temperature.
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U2 - 10.1021/acs.jpclett.0c00709
DO - 10.1021/acs.jpclett.0c00709
M3 - Article
C2 - 32223166
AN - SCOPUS:85083546693
VL - 11
SP - 2917
EP - 2924
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 8
ER -