Yield of In_xGa_(1-x)As superlattices under bending and nanoindentation

摘要

A series of In_xGa_(1-x)As superlattices grown on InP substrates with differing coherency strains have been deformed by bending at 500 degC and by nanoindentation at room temperature.The deformation was characterized by transmission electron microscopy through examination of thin sections machined in a foused ion beam microscope.The bent samples sheared along [11] planes,and the most highly strained samples partially relaxed through the formation of misfit dislocations.Under indentation the majority of the plastic strain in the multilayers is accommodated by twinning whereas no twins were observed under indents in the InP substrate.The overall dimensions of the plastic zone increased linearly with indent load.