In combination with instrumented indentation, spectroscopic analysis of the indented region enables the study at the crystallographic and molecular level of the kinetics and processes involved in the mechanical deformation of materials, e.g. strain build up, phase transformations, and changes in crystallinity or density. However, many of the phenomena occurring during indentation can only be observed in their entirety and analyzed in depth under in situ conditions.

For that purpose, Raman spectroscopy-enhanced indentation technique (RS-IT) is being developed at NIST which combined instrumented indentation with Raman spectroscopy to analyze in-situ the structural changes of materials during indentation deformation. Recently, this methodology has been employed in in-situ studies on the phase transformation of crystalline and amorphous silicon thin films and the densification of the network structure of silicate glasses.

This research opportunity will focus on:     

• Developing novel capabilities for RS-IT methodology tailored to specific groups of materials with focus on semiconductors, glasses and/or molecular crystals,
• Conducting in situ studies on the structural changes in the materials during indentation-induced deformation with focus on semiconductors, glasses and/or molecular crystals.

These measurements will be very helpful in advancing the understanding of the deformation behavior of materials in complex stress conditions and refining of contact models and related simulation studies. Further, the RS-IT methodology has the potential of a broad impact across a wide range of industries including semiconductor, glass and pharmaceutical sectors.                                                                              

key words

Raman spectroscopy; Fluorescence spectroscopy; nanoindentation; in-situ measurements; structural characterization; mechanical characterization; mechanical stresses and strains; structure-property correlation; semiconductors; glasses; molecular crystals

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants