Probing and modeling of pressure-induced coordination transformation in borate glasses: Inelastic x-ray scattering study at high pressure

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Phys. Rev. B

DOI:https://doi.org/10.1103/PhysRevB.78.214203· OSTI ID:1007005

Lee, Sung Keun; Eng, Peter J; Mao, Ho-kwang; Shu, Jinfu ^[1]

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1. SNU

Here, we report on the in situ synchrotron inelastic x-ray scattering spectra of Na-borate glasses at high pressure up to 25 GPa. The pressure-induced boron coordination transformation from {sup [3]}B to {sup [4]}B is linear with pressure characterized by a single value of ({partial_derivative}{sup [3]}B/{partial_derivative}P){sub T}. Previous studies of Li-borate and pure-borate glasses show a nonlinear transformation with multiple ({partial_derivative}{sup [3]}B/{partial_derivative}P){sub T} values for different pressure ranges, revealing the important role cation field strength plays in densification and pressure-induced structural changes. Considering the distribution of the energy difference beween low- and high-pressure states ({Delta}{var_epsilon}) in the energy landscape and the variance of the ratio {Delta}{var_epsilon} to its pressure gradient ({partial_derivative}{Delta}{var_epsilon}/{partial_derivative}P){sub T} as a measure of network flexibility with pressure, an amorphous system with a large variance in {Delta}{var_epsilon} at 1 atm and/or a small ({partial_derivative}{Delta}{var_epsilon}/{partial_derivative}P){sub T} may undergo a gradual coordination transformation (e.g., Na borates). In contrast, a system with the opposite behavior (e.g., Li borates) undergoes an abrupt coordination transformation. The results and concepts of this study thus can shed light on opportunities to study the effect of composition on the nature of densification in low-z oxide and other archetypal glasses and melts.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1007005
• Journal Information: Phys. Rev. B, Journal Name: Phys. Rev. B Journal Issue: (21) ; 2008 Vol. 78; ISSN 1098-0121
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

43 PARTICLE ACCELERATORS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORATES
BORON
CATIONS
DISTRIBUTION
GLASS
INELASTIC SCATTERING
OXIDES
PRESSURE DEPENDENCE
PRESSURE GRADIENTS
PRESSURE RANGE GIGA PA
SCATTERING
SIMULATION
SODIUM COMPOUNDS
SYNCHROTRON RADIATION
TRANSFORMATIONS
X-RAY SPECTRA