1. Rheology of amorphous olivine thin films characterized by nanoindentation.
- Author
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Baral, Paul, Orekhov, Andrey, Dohmen, Ralf, Coulombier, Michaël, Raskin, Jean Pierre, Cordier, Patrick, Idrissi, Hosni, and Pardoen, Thomas
- Subjects
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NANOINDENTATION , *THIN films , *VISCOPLASTICITY , *OLIVINE , *PULSED laser deposition , *RHEOLOGY , *CRYSTAL grain boundaries - Abstract
The rheological properties of amorphous olivine thin films deposited by pulsed laser deposition have been studied based on ambient temperature nanoindentation under constant strain-rate as well as relaxation conditions. The amorphous olivine films exhibit a viscoelastic-viscoplastic behavior with a significant rate dependency. The strain-rate sensitivity m is equal to ∼ 0.05 which is very high for silicates, indicating a complex out-of-equilibrium structure. The minimum apparent activation volume determined from nanoindentation experiments corresponds to Mg and Fe atomic metallic sites in the (Mg,Fe) 2 SiO 4 crystalline lattice. The ambient temperature creep behavior of the amorphous olivine films differs very much from the one of single crystal olivine. This behavior directly connects to the recent demonstration of the activation of grain boundary sliding in polycrystalline olivine following grain boundary amorphization under high-stress. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
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