Magnetic properties and fine analysis of low dimensional matter

A.Y. 2020/2021
Overall hours
Learning objectives
The purpose of the course is to introduce the magnetic properties of matter also as a function of dimensionality (surface ferromagnetism and nano-magnetism) and of the experimental fine analysis methods based on radiation-matter interaction (X-rays, Soft-X-rays, neutrons, electrons). The course has both theory and experimental contents finalized to the comprehension and interpretation of data on magnetic and nano-magnetic systems. The course includes a final two-day stage in Trieste at the NFFA-IOM and Sincrotrone-Trieste. The theory of ferromagnetism is introduced discussion the Heisenberg hamiltonian, the Stoner model, the Ligand Field theory, and Molecular Field theory. The temperature dependence of the magnetization for bulk and surface ferromagnets. The spin polarization of an electron beam via Mott scattering and exchange scattering. The magnetostatics, domain walls (Bloch and Neel). Magnetization dynamics, Landau-Lifshitz-Gilbert equation. Introduction to Fine Analysis of matter: interaction of quantons and matter, sources of EM radiation, synchrotron radiation, Free Electron Laser, diffractive methods, X-ray crystallography, scanning probe microscopy, photoelectron spectroscopy, angle and spin resolved, X-ray absorption and magnetic dichroism spectroscopy and magnetometry
Expected learning outcomes
At the end of the course the student will be able to:
-know the foundations of description of magnetic order in matter;
-know the foundations of the main theories and their domain of application;
-will understand both classical and modern experiments on magnetic properties of matter;
-will know the principles of fine analysis experiments;
-will orient in the contemporary literature on magnetism of low dimensional matter.
Course syllabus and organization

Single session

Lesson period
First semester
The course will be delivered entirely in remote mode if the limitations to mobility due to the COVID-19 will persist. The lectures will be offered in virtual classrooms (on ZOOM) in synchronous connection, with the possibility of real-time dialogue with the teacher.
If possible special sessions in presence of students and teacher will be prganized for discussion of the topics of the course and possible presentation by the students of scientfic papers as proposed by the teacher, related to the topics developed in the lectures. This possibility will be agreed with the students as far as timing and logistics.
Course syllabus
1. Introduction to ferromagnetism
2. Mean field approximation
3. Heisenberg's Hamiltonian, bulk and surface
4. Temperature depencence of Magnetization, in the bulk and for low dimensional systems
5. Spin Polarization SP measurement methods and SP vs. T in bulk and surface ferromagnets
6. Magnetic anisotropy
7. Magnetostatics, domain walls (Bloch and Néel)
8. Magnetization dynamics, Landau-Lifshiz-Gilbert equation
9. Symmetries at surfaces
10. Surface melting, theory and experiments of Franck and van der Veen
11. Introduction to fine analysis
12. Interaction of quantons with matter (X-rays -soft and Hard-, electrons, neutrons)
13. Sources of EM radiation, synchrotron light, Free Electron Laser, Laser-HHG
14. Diffraction, X-crystallography, surface crystallography, the phase problem and reconstruction methods
15. Scanning probe microscopy, STM, AFM
16. Surface relaxation and reconstruction
17. Tunnel spectroscopy with a tip STS
18. Photoelectron spectroscopy, integrated, energy resolved, angularly resolved, spin resolved
19. X-ray Absorption Spectroscopy and magnetometry XMCD, XMLD
20. Time resolved spectroscopy and pump/probe methods
21. Final 2-3 day stage at Elettra, FERMI@Elettra and NFFA-IOM CNR at Trieste
Prerequisites for admission
General physics (electromagnetism and special relativity), knowledge of structure of matter or solid state physics.
Teaching methods
Front lectures and final stage at Trieste visiting the NFFA-IOM CNR and Elettra synchrotron radiation laboratory
Teaching Resources
J.Stohr, H.C. Siegmann MAGNETISM, from fundamentals to nanoscience dynamics. Springer ISSN 0171-1873
Various articles and PPT presentations made available during the course
Assessment methods and Criteria
The oral examination is a discussion on topics dealt with during the course. In about one hour it may be siscussed an hypothetical research project, its theoretical and experimental implications, within the domains of the course.
FIS/03 - PHYSICS OF MATTER - University credits: 6
Lessons: 42 hours
Professor: Rossi Giorgio