Fast and quantitative 2D and 3D orientation mapping using Raman microscopy

Oleksii Ilchenko,Florian Bachmann,Roman Slipets,Matteo Todeschini,Yuriy Pilgun,Henning Friis Poulsen,Anja Boisen,Andrii Kutsyk,Peter Ouma Okeyo

doi:10.1038/s41467-019-13504-8

Abstract

Non-destructive orientation mapping is an important characterization tool in materials science and geoscience for understanding and/or improving material properties based on their grain structure. Confocal Raman microscopy is a powerful non-destructive technique for chemical mapping of organic and inorganic materials. Here we demonstrate orientation mapping by means of Polarized Raman Microscopy (PRM). While the concept that PRM is sensitive to orientation changes is known, to our knowledge, an actual quantitative orientation mapping has never been presented before. Using a concept of ambiguity-free orientation determination analysis, we present fast and quantitative single-acquisition Raman-based orientation mapping by simultaneous registration of multiple Raman scattering spectra obtained at different polarizations. We demonstrate applications of this approach for two- and three-dimensional orientation mapping of a multigrain semiconductor, a pharmaceutical tablet formulation and a polycrystalline sapphire sample. This technique can potentially move traditional X-ray and electron diffraction type experiments into conventional optical laboratories.

Highlights

Non-destructive orientation mapping is an important characterization tool in materials science and geoscience for understanding and/or improving material properties based on their grain structure
Electron backscattering diffraction (EBSD) is a widespread technique for such orientation mapping[1,2], but as a surface-based method, it can only be extended to 3D by serial sectioning
The orientation determination results were obtained by fitting Euler angles to simulated data and were represented in a crystallographic color code using MTEX toolbox for Matlab[51,52], see Supplementary Fig. 5

Summary

Introduction

Non-destructive orientation mapping is an important characterization tool in materials science and geoscience for understanding and/or improving material properties based on their grain structure. We demonstrate orientation mapping by means of Polarized Raman Microscopy (PRM). We demonstrate applications of this approach for twoand three-dimensional orientation mapping of a multigrain semiconductor, a pharmaceutical tablet formulation and a polycrystalline sapphire sample This technique can potentially move traditional X-ray and electron diffraction type experiments into conventional optical laboratories. Electron backscattering diffraction (EBSD) is a widespread technique for such orientation mapping[1,2], but as a surface-based method, it can only be extended to 3D by serial sectioning It has challenges in the analysis of semiconductors and dielectric materials[1]. Polarized Raman microscopy (PRM) has the potential to be developed into a relatively cheap orientation mapping technique[9], with a diffraction-limited spatial resolution of around 200 nm[10].

Methods

Results

Conclusion