Spectroscopic Investigation of Silicon Polymorphs Formed by Indentation

Silicon polymorphs have been prepared by means of scratching or indentation of Si(100) surfaces. Different indenter types have been used in order to validate the independence of silicon polymorph formation from indenter geometry. The formation of silicon polymorphs could be verified by registering the loading-displacement curves. Related to the maximum loads applied, only the formation of the meta-stable silicon phases SI-III, Si-IV and Si-XII has been observed, what has been verified by Raman spectroscopy. Four different ways of the preparation of electron transparent samples are presented and compared. Finally, a first electron energy loss spectrum of certain silicon polymorphs is shown.