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Plasticity of M G S I O 3 perovskite: The results of microhardness tests on single crystals
Author(s) -
Karato Shunichiro,
Fujino Kiyoshi,
Ito Eiji
Publication year - 1990
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl017i001p00013
Subject(s) - knoop hardness test , materials science , vickers hardness test , indentation hardness , mineralogy , perovskite (structure) , enstatite , plasticity , composite material , shear modulus , anisotropy , crystallography , microstructure , geology , optics , chemistry , physics , meteorite , astronomy , chondrite
The Plasticity of single crystals of MgSiO 3 perovskite was studied (at room temperature) by the microhardness tests using a Vickers and a Knoop indenter. The Vickers hardness, H v , of MgSiO 3 perovskite was determined to be 18 +/− 2 GPa, about a factor of two larger than the hardness of either enstatite or olivine, indicating a significantly larger resistance to plastic flow of this mineral than that of the upper mantle minerals. The normalized hardness, H v /μ (μ: shear modulus), of MgSiO 3 perovskite is in reasonable agreement with those of titanate perovskites (SrTiO 3 , BaTiO 3 , CaTiO 3 ), although a cubic perovskite SrTiO 3 has a significantly lower hardness than others. The Knoop tests showed anisotropic hardness consistent with the slip systems .