3. Strength and rheology under compression

The yield strength of materials at high pressure has diverse applications to interpretation of static and dynamic experiments, understanding mechanical performance, and constraining the rheology of planetary interiors. Quantitative measurements of static strengths achieved in the diamond anvil cell can be made using x-ray diffraction in a radial geometry for samples under non-hydrostatic compression. We have used this method to explore deformation behavior (texture development, strength, slip systems) of post-perovskite phases (MgGeO3, (Mg,Fe)SiO3) at pressures above 1 Mbar. We have also studied the behavior of a suite of strong ceramics including oxides, silicates, borides, and nitrides.

Collaborators in this area include S. Merkel (Lille), R. Wenk (Berkeley), and L. Miyagi (Yale)

Selected References:
Merkel, S., A. K. McNamara, A. Kubo, S. Speziale, L. Miyagi, Y. Meng, T. S. Duffy, and H.-R. Wenk, Deformation of (Mg,Fe)SiO3 post-perovskite and modeling of D" anisotropy, Science, 316, 1729-1732, 2007.

Duffy, T. S., Strength of materials under static loading in the diamond anvil cell, in Shock Compression of Condensed Matter – 2007, edited by M. D. Furnish, M. L. Elert, T. P. Russell, and C. T. White, AIP, New York, 639-644, 2007.

He, D. W., S. R. Shieh and T. S. Duffy, Equation of state and strength of boron suboxide from radial x-ray diffraction in a diamond cell under nonhydrostatic compression, Physical Review B, 70, 184121, 2004.

Duffy Group
High-Pressure Mineral Physics and Materials Science Laboratory
Department of Geosciences
Princeton University