Chapter 1
X-Ray Birefringence Imaging (XBI):
A New Technique for Spatially Resolved
Mapping of Molecular Orientations
in Materials
Kenneth D. M. Harris, Rhian Patterson, Yating Zhou, and Stephen P. Collins
Abstract The X-ray birefringence imaging (XBI) technique, first reported in 2014,
is a sensitive method for spatially resolved mapping of the local orientational properties of anisotropic materials. In the case of organic materials, the technique may be
applied to study the orientational properties of individual molecules and/or bonds,
including the study of changes in molecular orientations associated with order–
disorder phase transitions and characterization of phase transitions in liquid crystalline materials. This chapter presents a basic introduction to the XBI technique,
giving a qualitative description of the fundamentals of the technique and discussing
experimental aspects of the measurement of XBI data. Several examples are presented
to highlight the application of the technique to study the orientational properties of
molecules in organic materials.
Keywords X-ray birefringence imaging · Molecular orientations · Solid inclusion
compounds · Liquid crystals · Anisotropic materials
1.1 Introduction
The polarizing optical microscope, invented in the nineteenth century, continues to
be used extensively to investigate the structural anisotropy of materials across a
wide range of scientific disciplines, including mineralogy, crystallography, materials
sciences, and biological sciences. The polarizing optical microscope is based on
the phenomenon of optical birefringence [1–3]—i.e., for linearly polarized light
propagating through an anisotropic material, the refractive index depends on the
orientation of the material with respect to the direction of polarization of the incident
light.
K. D. M. Harris (B) · R. Patterson · Y. Zhou
School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales, UK
e-mail: HarrisKDM@cardiff.ac.uk
R. Patterson · S. P. Collins
Diamond Light Source, Harwell Science and Innovation Campus, Didcot,
Oxfordshire OX11 0DE, England, UK
© Springer Nature Singapore Pte Ltd. 2020
M. Sakamoto and H. Uekusa (eds.), Advances in Organic Crystal Chemistry,
https://doi.org/10.1007/978-981-15-5085-0_1
3
X-Ray Birefringence Imaging (XBI):
A New Technique for Spatially Resolved
Mapping of Molecular Orientations
in Materials
Kenneth D. M. Harris, Rhian Patterson, Yating Zhou, and Stephen P. Collins
Abstract The X-ray birefringence imaging (XBI) technique, first reported in 2014,
is a sensitive method for spatially resolved mapping of the local orientational properties of anisotropic materials. In the case of organic materials, the technique may be
applied to study the orientational properties of individual molecules and/or bonds,
including the study of changes in molecular orientations associated with order–
disorder phase transitions and characterization of phase transitions in liquid crystalline materials. This chapter presents a basic introduction to the XBI technique,
giving a qualitative description of the fundamentals of the technique and discussing
experimental aspects of the measurement of XBI data. Several examples are presented
to highlight the application of the technique to study the orientational properties of
molecules in organic materials.
Keywords X-ray birefringence imaging · Molecular orientations · Solid inclusion
compounds · Liquid crystals · Anisotropic materials
1.1 Introduction
The polarizing optical microscope, invented in the nineteenth century, continues to
be used extensively to investigate the structural anisotropy of materials across a
wide range of scientific disciplines, including mineralogy, crystallography, materials
sciences, and biological sciences. The polarizing optical microscope is based on
the phenomenon of optical birefringence [1–3]—i.e., for linearly polarized light
propagating through an anisotropic material, the refractive index depends on the
orientation of the material with respect to the direction of polarization of the incident
light.
K. D. M. Harris (B) · R. Patterson · Y. Zhou
School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales, UK
e-mail: HarrisKDM@cardiff.ac.uk
R. Patterson · S. P. Collins
Diamond Light Source, Harwell Science and Innovation Campus, Didcot,
Oxfordshire OX11 0DE, England, UK
© Springer Nature Singapore Pte Ltd. 2020
M. Sakamoto and H. Uekusa (eds.), Advances in Organic Crystal Chemistry,
https://doi.org/10.1007/978-981-15-5085-0_1
3