Pressure and temperature dependence of the viscosi

Authors: Akio Suzuki Eiji Ohtani Hidenori Terasaki Keisuke Nishida Hiromi Hayashi Tatsuya Sakamaki Yuki Shibazaki Takumi Kikegawa

Publish Date: 2010/06/19

Volume: 38, Issue: 1, Pages: 59-64

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Abstract

The viscosity of a silicate melt of composition NaAlSi2O6 was measured at pressures from 16 to 55 GPa and at temperatures from 1350 to 1880°C We employed in situ falling sphere viscometry using Xray radiography We found that the viscosity of the NaAlSi2O6 melt decreased with increasing pressure up to 2 GPa The pressure dependence of viscosity is diminished above 2 GPa By using the relationship between the logarithm of viscosity and the reciprocal temperature the activation energies for viscous flow were calculated to be 37 ± 04 × 102 and 37 ± 05 × 102 kJ/mol at 22 and 29 GPa respectivelyThe authors thank Dr Kenichi Funakoshi at SPrign8 for technical supports The synchrotron radiation experiments were conducted at the Photon Factory KEK Proposal No 2007S2–002 This work was partially supported by GrantinAid for scientific research from the Japanese Ministry of Education Culture Sports Science and Technology to AS No 17654102 21684032 and 20103003 and to EO No 16075202 and 18104009

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