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Published on: September 17, 2021
Structural Evolution of SiO_{2} Glass with Si Coordination Number Greater than 6
Yoshio Kono1,2, Yu Shu3, Curtis Kenney-Benson3
1Geophysical Laboratory, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
Abstract:
Pair distribution function measurement of SiO_{2} glass up to 120 GPa reveals changes in the first-, second-, and third-neighbor distances associated with an increase in Si coordination number C_{Si} to >6 above 95 GPa. Packing fractions of Si and O determined from the first- and second-neighbor distances show marked changes accompanied with the structural evolution from C_{Si}=6 to >6. Structural constraints in terms of ionic radius ratio of Si and O, and ratio of nonbonded radius to bonded Si─O distance support the structural evolution of SiO_{2} glass with C_{Si}>6 at high pressures.
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