Beyond simple imaging with energetic beams – nanopatterning, correlative microscopy and statistical analysis of inclusions

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dc.contributor.advisor Holmes, Justin D. en
dc.contributor.advisor Petkov, Nikolay en Schmidt, Michael 2015-11-23T11:09:03Z 2015-11-23T11:09:03Z 2015 2015
dc.identifier.citation Schmidt, M. 2015. Beyond simple imaging with energetic beams – nanopatterning, correlative microscopy and statistical analysis of inclusions. PhD Thesis, University College Cork. en
dc.identifier.endpage 137
dc.description.abstract Electron microscopy (EM) has advanced in an exponential way since the first transmission electron microscope (TEM) was built in the 1930’s. The urge to ‘see’ things is an essential part of human nature (talk of ‘seeing is believing’) and apart from scanning tunnel microscopes which give information about the surface, EM is the only imaging technology capable of really visualising atomic structures in depth down to single atoms. With the development of nanotechnology the demand to image and analyse small things has become even greater and electron microscopes have found their way from highly delicate and sophisticated research grade instruments to key-turn and even bench-top instruments for everyday use in every materials research lab on the planet. The semiconductor industry is as dependent on the use of EM as life sciences and pharmaceutical industry. With this generalisation of use for imaging, the need to deploy advanced uses of EM has become more and more apparent. The combination of several coinciding beams (electron, ion and even light) to create DualBeam or TripleBeam instruments for instance enhances the usefulness from pure imaging to manipulating on the nanoscale. And when it comes to the analytic power of EM with the many ways the highly energetic electrons and ions interact with the matter in the specimen there is a plethora of niches which evolved during the last two decades, specialising in every kind of analysis that can be thought of and combined with EM. In the course of this study the emphasis was placed on the application of these advanced analytical EM techniques in the context of multiscale and multimodal microscopy – multiscale meaning across length scales from micrometres or larger to nanometres, multimodal meaning numerous techniques applied to the same sample volume in a correlative manner. In order to demonstrate the breadth and potential of the multiscale and multimodal concept an integration of it was attempted in two areas: I) Biocompatible materials using polycrystalline stainless steel and II) Semiconductors using thin multiferroic films. I) The motivation to use stainless steel (316L medical grade) comes from the potential modulation of endothelial cell growth which can have a big impact on the improvement of cardio-vascular stents – which are mainly made of 316L – through nano-texturing of the stent surface by focused ion beam (FIB) lithography. Patterning with FIB has never been reported before in connection with stents and cell growth and in order to gain a better understanding of the beam-substrate interaction during patterning a correlative microscopy approach was used to illuminate the patterning process from many possible angles. Electron backscattering diffraction (EBSD) was used to analyse the crystallographic structure, FIB was used for the patterning and simultaneously visualising the crystal structure as part of the monitoring process, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to analyse the topography and the final step being 3D visualisation through serial FIB/SEM sectioning. II) The motivation for the use of thin multiferroic films stems from the ever-growing demand for increased data storage at lesser and lesser energy consumption. The Aurivillius phase material used in this study has a high potential in this area. Yet it is necessary to show clearly that the film is really multiferroic and no second phase inclusions are present even at very low concentrations – ~0.1vol% could already be problematic. Thus, in this study a technique was developed to analyse ultra-low density inclusions in thin multiferroic films down to concentrations of 0.01%. The goal achieved was a complete structural and compositional analysis of the films which required identification of second phase inclusions (through elemental analysis EDX(Energy Dispersive X-ray)), localise them (employing 72 hour EDX mapping in the SEM), isolate them for the TEM (using FIB) and give an upper confidence limit of 99.5% to the influence of the inclusions on the magnetic behaviour of the main phase (statistical analysis). en
dc.description.sponsorship Enterprise Ireland (IP/2011/0130) en
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher University College Cork en
dc.rights © 2015, Michael Schmidt. en
dc.rights.uri en
dc.subject Stents en
dc.subject Multiscale en
dc.subject Multimodal en
dc.subject Multiferroics en
dc.subject Aurivillius phase materials en
dc.subject Perovskites en
dc.subject Catalysis en
dc.subject Thin films en
dc.subject Trace analysis en
dc.subject Surface patterning en
dc.subject Electron microscopy en
dc.subject Statistical analysis en
dc.subject Nanopatterned stainless steel en
dc.subject Correlative microscopy en
dc.subject Serial sectioning FIB-SEM en
dc.subject Second phase inclusions en
dc.subject Focused ion beam (FIB) en
dc.subject Energy dispersive x-ray spectroscopy (EDXS) en
dc.subject Transmission electron microscopy (TEM) en
dc.subject High-index faceted palladium (Pd) nanoparticles en
dc.title Beyond simple imaging with energetic beams – nanopatterning, correlative microscopy and statistical analysis of inclusions en
dc.type Doctoral thesis en
dc.type.qualificationlevel Doctoral en
dc.type.qualificationname PhD (Science) en
dc.internal.availability Full text available en No embargo required en
dc.description.version Accepted Version
dc.contributor.funder Enterprise Ireland en
dc.description.status Not peer reviewed en Chemistry en Tyndall National Institute en
dc.check.type No Embargo Required
dc.check.reason No embargo required en
dc.check.opt-out No en
dc.thesis.opt-out false
dc.check.embargoformat Not applicable en
dc.internal.conferring Summer Conferring 2015

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