Application of precision engineering for nanometre focussing of hard X-rays in synchrotron beam lines

This thesis was submitted for the degree of Master of Philosophy and awarded by Brunel University.Many modern synchrotron beamlines are able to focus X-rays to a few microns in size. Although the technology to achieve this is well established, performing routine experiments with such beams is still time consuming and requires careful set up. Furthermore there is a need to be able to carry out experiments using hard X-ray beams with even smaller beams of between 100nm and 10nm. There are focussing optics that are able to do this but integrating these optics into a stable and a usable experimental set up are challenging. Experiments can often take some hours and any change in position of the beam on the sample will adversely affect the quality of the results. Experiments will often require scanning of the beam across the sample and so mechanisms suitable for high resolution but stable scanning are required. Performing routine experiments with nanometre sized beams requires mechanical systems to be able to position the sample, focussing optics, detectors and diagnostics with significantly higher levels of stability and motion resolution than is required from so called micro focus beam lines. This dissertation critically reviews precision engineering and associated technologies that are relevant for building nano focus beamlines, and the following key issues are explored: • Long term position stability due to thermal effects • Short term position stability due to vibration • Position motion with nanometre incremental motion • Results of some tests are presented and recommendations given. Some test results are presented and guidance on designing nano focus beamlines presented.Diamond Light Sourc

Electromechanical Properties of 3D Multifunctional Nano-Architected Materials

In this thesis, we explore the fabrication and characterization of 3D architected multifunctional materials in three different categories: varied density for tailored mechanical response, stiff ultra low-k dielectric materials, and direct laser writing of piezoelectric structures at the micron scale. The density of an architected material plays a large role in determining its effective Young’s modulus, strength, and deformation behavior. The first section of this work explores the effect of incorporating two density regions into hollow nanolattices, which results in two distinct mechanical response regions for horizontal interfaces and a combined varying response for a diagonal interface. The second section of this work describes low dielectric constant (low-k) materials, which have gained increasing popularity because of their critical role in developing faster, smaller, and higher performance devices. We report the fabrication of 3D nanoarchitected hollow-beam alumina dielectrics with a k value of 1.06 - 1.10 at 1 MHz that is stable over the voltage range of -20 to 20 V and a frequency range of 100 kHz to 10 MHz, with an effective Young’s modulus of 30 MPa, a strength of 1.07 MPa, a nearly full shape recoverability to its original size after &gt;50% compressions, and outstanding thermal stability with a thermal coefficient of dielectric constant (TCK) of 2.43 x 10-5K-1 up to 800° C. Finally, we report the fabrication of monolithic piezoelectric ZnO structures of arbitrary shape via a polymer complex route. We have confirmed the microstructure using XRD, TEM, and SAED, and have observed its electromechanical response using a novel in-situ experiment.</p

Materials Chemistry of Fullerenes, Graphenes, and Carbon Nanotubes

This Special Issue is intended as a platform for interactive material science articles with an emphasis on the preparation, functionalization chemistry, and characterization of nanocarbon compounds, as well as all aspects of physical properties of functionalized, conjugated, or hybrid nanocarbon materials, and their associated applications. Some recent advances in the field are here collected, providing new ideas for discussion of researchers working in this multidisciplinary scenario