The course will be done through lectures and some laboratory experiments which allow students to observe experimentally some theoretical topics covered during the course.
If lectures are given in a mixed or remote way, some changes may be introduced from what has been stated above, in order to comply with the programme envisaged and reported in the syllabus.
Course syllabus: Deposition techniques of thin films through chemical (chemical vapor deposition and metal-organic CVD, atomic layer deposition, chemical beam epitaxy, sol-gel) or physical processes (molecular beam epitaxy). Syntheses of nanostructures through vapour phase and solution approaches: effects of process parameters and the use of hard and soft templates. Materials/properties relationship for particular crystalline structures. Perovskite based materials and conduction properties: superconductors, dielectrics and ferroelectrics. Solid oxide fuel cells (SOFCs): electrodes and oxide and proton based conduction electrolytes. Characterization techniques in the fabrication of materials. X-ray diffraction (XRD) of powders, oriented and epitaxial films: phase identification, domain size, rocking curves and pole figures. Electron microscopies: principles and applications of SEM and base concepts of TEM. Energy dispersive X-ray analyses and wavelength dispersive X-ray analyses.
FRONTAL LESSONS (6 CFU)
ADVANCED SYNTHETIC METHODOLOGIES
Atomic layer deposition (ALD)
- Theoretical principles: temporal ALD and spatial ALD
- Case studies: simple oxide deposition (Al2O3); photonic crystal synthesis; deposition of multi-component systems.
Chemical Vapor Deposition (CVD) and Metal-Organic-CVD (MOCVD)
- Theoretical principles: transport phenomena; mechanisms and reaction kinetics; nucleation and growth.
- Case studies: deposition of simple oxides and multi-component oxides; fluoride film deposition.
- Processes of industrial interest: deposition of GaN, AlN and SiC.
Molecular beam epitaxy (MBE)
- Theoretical principles.
- Applications to the growth of epitaxial films.
Chemical Beam Epitaxy
- Theoretical principles and applications.
Sol-gel deposition techniques
- Theoretical principles.
- Applications to film synthesis, hybrid systems, nanoparticles by Stober process.
Precursors for vapor phase and solution processes
Synthesis of nano structured materials
- Definition of nanostructures.
- Synthetic approaches for the synthesis of nanostructures.
- Nanorod synthesis and vapor phase nanotubes.
- Synthesis of nanoparticles and solution nanostructures
Molecular layer deposition for the deposition of monolayers.
Notes on the synthesis of self-assembled monolayer from solution.
TYPES OF MATERIALS
- Perovskite structure
- Structure description and tolerance factor
- Perovskites with ionic conduction properties
- Description of ionic conductivity of intrinsic and extrinsic type.
- Solid oxide fuel cells.
Perovskites with dielectric properties
- Piezoelectric, pyroelectric and ferroelectric.
- Applications in energy harvester.
- Notes on piezotronic, piezophotonic and piezo-phototronic
Perovskite-based materials with superconducting properties
- Basic and superconducting principles I and II type. -
- Outline of BCS theory.
- Case studies of systems based on high Tc superconductors
- Information obtainable from a diffractogram: amorphous or crystalline nature, phase identification, grain size.
- Crystalline lattices and systematic absences.
- Diffractions from powders and thin films: calculation of cell parameters.
- Notes on the single crystal: Ewald sphere.
- Advanced characterization of materials: rocking curves and polar figures in the characterization of oriented and epitaxial samples
Electronic scanning microscopy
- General principles.
- Tungsten filament electron beam, LaB6 crystal, or FEG (Field Emission Gun).
- Volume of interaction, elastic and inelastic events, species produced.
- Detector of secondary and backscattered electrons.
EDX Microanalysis (Energy Dispersive X-ray Analysis)
- Detector type
- Qualitative and quantitative analysis (ZAF method).
- Maps and scan-lines via EDX.
WDX (Wavelength Dispersive X-ray Analysis) microanalysis
- Spectrometer and crystal type description
- Qualitative and quantitative analysis.
- Advantages and disadvantages of the two microanalysis
LABORATORY EXPERIMENTS (2 CFU)
Experiments carried out:
1) syntheses of precursors: Sr(hfa)2tetraglyme, La(hfa)3diglyme, Ni(tta)2tmeda, Eu(tta)3phen;
2) Characterization of physico-chemical properties of synthesized precursors (m.p., FT-IR and UV-Vis spectra; thermogravimetric analyses);
3) Fabrication of oxides and fluoride or oxyfluoride films through MOCVD;
4) Application of the europium complex to the formation of a luminescent hybrid layer as solar concentration;
5) Morphological (SEM) and compositional (EDX) characterization of synthesized materials;
6) Structural characterization through XRD of synthesized materials.
Lanthanides and rare earths: unknown elements in everyday life
1) A. R. West “Basic Solid State Chemistry and its Applications” Wiley, 2012;
2) B. D. Fahlman “Materials Chemistry” 3rd Edition, Springer, 2018;
3) Editor R. Fisher, "Precursor Chemistry of Advanced Materials: CVD, ALD and Nanoparticles", Springer, 2010.
4) L. V. Interrante e M. J. Hampden-Smith Chemistry of Advanced Materials Wiley-VCH, 1998.