SPECTROSCOPY OF MATERIALS
Learning outcomes of the course unit
[Knowledge and understanding] To know the physical mechanisms underlying the main spectroscopic techniques and the detailed operation of dispersive and interferometric spectrometers.
[Applied knowledge and understanding] To evaluate the choice of techniques that can be used depending on the type of material to be studied, the physical parameters to be investigated, the energy range and the spatial and temporal scale. Knowing how to take a measurement with a Raman spectrometer.
[Learning skills] Learning the use of some spectroscopic techniques, in particular Raman spectroscopy. Acquire and interpret spectral data, compare them with databases and reference literature.
[Making judgments] To evaluate if the technique used is able to provide the required results. Recognize and deal with the main sources of error and noise. Integrate data from different techniques.
[Ability to communicate] To present experimental data correctly, separating raw data from interpretations. Use of correct scales, units of measurement and terminology.
Geometrical and wave optics. Interference and diffraction. Electromagnetism. Basic elements of chemistry and structure of the matter.
Course contents summary
The course aims to provide a knowledge of the main spectroscopic techniques for the analysis of materials, with particular detail in the techniques operating from infrared to ultraviolet, without neglecting the main information on the techniques operating in the other energy ranges.
After having recovered the indispensable skills of optics, electromagnetism, structure of matter and radiation-matter interaction, the theory necessary to understand the mechanisms underlying the main spectroscopies and the technology used in modern spectrometers will be deepened.
The skills provided must enable students to use the spectroscopic techniques operatively, both from the point of view of the choice of techniques appropriate to the problems to be solved, and in terms of knowledge of the various components and their characteristics.
In order to make the competences more operative, much space will be given to the study of a technique, Raman spectroscopy, both from a theoretical and practical point of view. The detailed analysis of the principles, of the instrumentation, of the sources of error and noise, of data processing, will provide in-depth skills easily generalized to other techniques. The laboratory activities will be carried out in small groups on real problems concerning high technology materials.
Recovery of the main elements of physical optics and radiation-matter interaction, with particular attention to the range between the far infrared and ultra-violet. Absorption, emission, diffusion and related processes in molecular and crystalline systems. Rotational, vibrational and electronic excitations.
Spectroscopies for the study of materials: overview of the main spectroscopic techniques according to the type of excitation and probe. What information (structural, compositional) can be obtained.
Subdivision of spectroscopic techniques based on the studied materials and on the types of analyzed samples: phase (solid, liquid, gaseous, crystalline, molecular, amorphous), composition (organic, inorganic), geometry (bulk, film, powders, macro, micro) . Sampling modes and measurement configurations, spatial and temporal resolution.
Dispersive spectrometers: general scheme and main components.
Diffraction gratings, input and output optics, detectors, sources, filters.
Efficiency and spectral response of the various components.
Interferometer. Fourier Transform spectroscopy.
Detailed presentation of the main spectroscopic techniques for the study of materials (mainly with IR-Visible probe).
Raman spectroscopy. Theory and technique.
Selection rules, vibrations and symmetries.
Notes of the teacher (ppt/pdf) available on the platform "Elly". Further texts or book chapters will be identified douring the course.
Traditional frontal lessons with slides, with material accessible on the ELLY platform. Spectroscopy laboratory in small groups. Use of portable micro-Raman and Raman spectrometers for case study resolution. First-person involvement of students.
Assessment methods and criteria
The degree of learning will be continuously evaluated in itinere with the active involvement of the students, in particular during laboratory activities. At the end of the course, the students will present a report on the experimental part, on which will be based about a quarter of the evaluation. Evaluation interview aimed at verifying the understanding of the main aspects of the theory related to physical phenomena and spectroscopic techniques. The oral exam weighs about ¾ of the final judgment.