ANALYTICAL CHEMISTRY OF SURFACES AND INTERPHASES
Learning outcomes of the course unit
To provide the fundamental concepts on the properties and reactivity of surfaces, with reference to the new materials. Highlights the main analytical techniques for interphases and surface characterisation and their proper use.
Knowledge of modern instrumental analytical chemistry
Course contents summary
Definition of interphase and surface, bulk and (multi)layers materials
Classification of interphases
Classical and modern methodologies for the interphase characterisation: application field and information obtained.
Thickness of the interphase region.
Application fields: examples of reaction, processes and phenomena that involve the interphase concept.
Classification and main properties of interphases.
Surface preparation and modification, etching and deposition techniques.
Selective and non-selective chemical etchings.
Composition rules for the etching mixtures, ternary composition diagrams, viscosity and temperature effects.
Photoactivated chemical etchings.
Physical Vapour Deposition and Chemical Vapour Deposition.
Morphological characterisation of interphases: point, surface, localised and extended defects, defect propagation within the interphase.
Chemical characterisation of interphases: compositional inohomogeneity
Evaluation of functional characteristics.
Interactions betweens particles and matter. penetration in the interphase, diffusion and retrodiffusion
Lateral and axial diffusion.
Optical microscopy, metallographic microscope, illumination systems, fundamental parameters of optical microscopy, optical aberrations, bright and dark field microscopy, polarised and monochromatic light microscopy.
Combined use of optical microscopy and chemical etchings.
Quantitative analysis in optical microscopy, fundamentals of data acquisition and image digitalization systems, expert and non expert automatic recognition systems
Scanning Electronic Microscopy, basic instrumentation and working principle, maximum magnification, sample characteristics, limitations and sample preparation, detectors
Combined use of SEM, X-ray fluorescence and Auger electron spectroscopy.
Atomic force spectroscopy and profilometers.
Fundamentals of X-ray fluorescence, microprobe, the energy dispersive detector, applicative examples
Fundamentals of Auger electron spectroscopy, principles and instrumentation, application field and comparison with x-ray fluorescence, compositional profiles, examples and applications.
Fundamentals of other electron spectroscopies: ESCA, UPS.
The secondary ion mass spectroscopy (SIMS), principles and instrumentation, ion sources, qualitative and quantitative analysis, standard preparation, concentration profiles, repeatability problems.
Ellipsometry, principles and instrumentation, the spectroscopic ellipsometry, uses of the information obtained, data acquisition and handling.
The students will carry out practical work in the lab, mainly focused on fixing the concepts discussed in the first part, namely: surface reactivity as a function of homogeneity and morphology, influence of various parameters on non-selective etching, passivation of surfaces, evaluation of attach shapes in selective chemical etching.