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Published on: June 18, 2020
Instabilities in diamond under high shear stress
1Department of Physics, University of Texas, Austin, Texas 78712 and Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, CP 702, 30123-970, Belo Horizonte, MG, Brazil.
Abstract:
We investigate, through first-principles calculations, lattice instabilities induced in diamond by the application of high shear stresses. For shear stresses as low as 95 GPa a lattice instability will occur, leading to graphitelike layered structures. This effect is highly anisotropic. The reversal of the direction of the applied shear forces may cause a change of 80 GPa in the shear stress value at which the instability develops. The same reversal also causes different bonds to be broken, resulting in a drastic change in the orientation of the resulting graphitelike structures. We also find that an additional compressive stress of 50 GPa along the (111) direction does not eliminate the shear-induced instability.
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