The course is offered in a 10-CFU version (Plasmas  for Surface Micro and Nanostructuring + Physics of disordered materials), to which two 5-CFU courses (Plasmas  for Surface Micro and Nanostructuring, Physics of disordered materials) are offered jointly. The present detailed program defines aims, educational outcomes and syllabus for every joint course

Plasmas for Surface Micro and Nanostructuring first provides an introduction to the basic features of a plasma, at the level of advanced undergraduate students. Attention is focussed to plasma energetics and confinement that play a role to the design and performance of devices developed for plasma assisted surface treatments of materials. Different classes of processes for the treatment of materials, that make use of cold plasmas, from plasma assisted physical vapor deposition, to plasma assisted chemical vapor deposition, to dc, rf, magnetron sputtering, with the device configurations developed to overcome qualitative deposition/surface modification problems that arise when using cold plasmas are critically reviewed, paying attention to a critical exam of examples of materials for specific applications. Film/surface microstructure (columnar structure), its origin and its dependence on process parameters are discussed. Thermodynamic modeling of the initial stages of film deposition (island, layer, island+layer models) are reviewed. Along the treatment examples of nanostructured film surfaces prepared by different techniques are illustrated with reference to materials for microelectronics, for sensing and for advanced performances in agressive ambients.

Physics of disordered materials aims at introducing the physics of structurally disordered condensed matter, with attention to irradiation effects. After introducing the concepts of order, disorder and order parameter (long range), the basic mechanisms of structural modification upon irradiation of a crystal with energetic particles are addressed in the elastic collision regime. The phenomenology of the glass transition, including the interplay between thermodynamics and kinetics is studied before offering a robust overview over the main techniques of experimental investigation of structural disorder. Attention is then focused to the structure of clusters, taken as the constitutive bricks of disordered materials, to the synthesis of nanocrystalline and nanoglassy materials, discussing a selection of their peculiar properties, to quasicrystals, studying their relation to crystals and the features of the quasicrystalline-amorphous state transition. Anderson-Mott localization and fractal models of structurally disordered materials are introduced.

After attending the course and after a positive evaluation, the students are expected to:

concerning Plasmas  for Surface Micro and Nanostructuring:

1. know and manage the basic features of a plasma through simple quantitative evaluations

2. know and are able to critically describe the distinctive characteristics of each of the different plasma-assisted materials treatment techniques discussed

3. know the relevance and are able to exploit the possible application of different microstructures that can be obtained in a surface/film by one of the discussed treatments 

4. know and are able to describe the general features of growth of a film 

concerning Physics of disordered materials:

1. know and are able to describe the effect of energetic particle irradiation (elastic collision regime) on the disordering and the structural stability of a target

2.  know and are able to describe the phenomenology of the glass transition for different classes of non polymeric materials, considering the interplay between thermodynamic and kinetic aspects of the transition

3. know and are able to choose (in principle) among the main experimental techniques to study structural disorder and the kind of information each of them provides, in terms of investigation of short and medium range order in a structurally disordered material

4. know and are able to describe the basics of the physics of atomic clusters (inert gases and simple metals) and of quasicrystals in relation to their structure, as well as the essentials of transport in heavily disordered materials and its modeling (Anderson-Mott localization)

Plasmas for Surface Micro and Nanostructuring: 

1. Basics: plasma definition and parameters; Debye’s length; sheaths; plasma ionisation degree; plasma oscillations; role of external magnetic (B) and electric (E) fields; dynamics of charged particles in non-uniform E and B fields; particle scattering; confinement, lateral, parallel; guiding center approximation; mirror effect

2. Plasma assisted physical vapour deposition (PAPVD); Townsend discharge; stable modes of the discharge, plasma optimization; the role of metal species in the plasma: penning reactions; reactive plasma assisted processes; impurities and their role

3. Plasma assisted chemical vapour deposition (PACVD); non-equilibrium chemistry in plasma volume; plasma-surface interactions; exotic, non-equilibrium phases and nanostructured films

4. Physical mechanisms of sputtering; angular dependences; surface topographical modifications; cluster sputtering; dc-sputtering, rf-sputtering, polarised sputtering, magnetron sputtering, unbalanced sputtering, closed field magnetron sputtering

5. Pulsed laser ablation – deposition: laser parameters and their role; laser radiation-target interaction: absorption, reflection, transport; plasma plume formation and interaction with the laser pulse; plume adiabatic expansion and propagation; plume condensation on a substrate and film growth; synthesis of nanoparticles and nanostructured films

6. Deposition parameters and microstructure evolution in thin films: columnar microstructure; Zone diagram; atomic shadowing; film nucleation and growth: island, layer, layer+island modes of growth  

Physics of disordered materials:

1. structural order; kinds of disorder; ordering rules; long range order parameters
2. phenomenology of the glass transition; thermodynamic and kinetic concepts; glass forming ability (GFA) criteria
3. physical mechanisms of structural modification upon energetic particle bombardment:
• electrons: RCS
• ions (elastic regime): linear versus dense collision cascade    
• microscopic analysis of the space-time evolution of a collision cascade
• GFA in irradiated materials: interpretative and predictive criteria
4. experimental techniques for the analysis of structural disorder: (a), elements of scattering theory; scattering from structurally disordered materials; (b), X-ray absorption spectroscopies: EXAFS; XANES; (c), vibrational spectroscopies: IR absorption and Raman scattering
5. (a), short range order (CSRO; TSRO); (b), medium range order (MRO); (c), atomic clusters; fullerene; fullerite; hollow diamonds
6. (*) nanocrystalline materials; structure and role of the interfaces; nanoglasses; synthesis of nanostructured materials via irradiation; nanostructured material response to irradiation
7. (*) quasicrystals: discovery, definition, aperiodic and quasi-periodic lattices; real quasicrystals; nano-quasicrystals; quasicrystal-amorphous and the reverse transition
8. (*) transport in heavily disordered materials: the Anderson-Mott localization; historical introduction; conducting vs localized electrons; the metal-insulator transition; localization of light: from ballistic to diffusive transport to Anderson localization; localization and enhanced transport in quasicrystals

Every year will be selected either section 6*, or section 7*, or section 8*.

For Plasmas for Surface Micro and Nanostructuring: Basics of electromagnetism, including Maxwell's equations and the propagation of plane waves in vacuum.

For Physics of disordered materials: Basics of crystal theory 

The evaluation consists in an oral examination that points at verifying the knowledge of the course topics, with particular reference to the ability in interpreting the physical bases of the different topics.  The candidate will be able to demonstrate that he knows, has understood, is able to describe, using the appropriate language and mathematical formalism, the contents of the course. In particular the exam aims at verifying that the candidate :

For Plasmas for Surface Micro and Nanostructuring: 

1. knows and is able to manage the basic features of a plasma through simple quantitative evaluations

2. knows and is able to illustrate the distinctive characteristics of each of the different plasma-assisted materials treatment techniques discussed

3. knows and is able to critically exploit the importance and the possible application of different microstructures that can be obtained in a surface/film by one of the discussed treatments, as well as the main features characterising the growth of a film. The knowledge and appropriate use of a set of physical constants (given at the beginning of the course) and of the SI physical units in simple quantitative estimates is required.

For Physics of disordered materials:

1. knows and is able to discuss the effect of energetic particle irradiation (elastic collision regime) on the structural stability of a target, analysing the degree of structural order via the use of an appropriate order parameter

2.  knows and is able to discuss the phenomenology of the glass transition for different classes of (non polymeric) materials and the interplay between thermodynamic and kinetic aspects of the transition 

3. knows and is able to choose in principle among the main experimental techniques to study structural disorder and the kind of information each of them provides to analyse short and medium range order in a structurally disordered material

4. knows and is able to discuss the basics of the physics of atomic clusters and quasicrystals and the models for their structural evolution and stability, as well as the basics of transport in heavily disordered materials and its modeling