1) Magnetic interactions in molecular systems: single ion electronic levels, exchange and dipolar interaction, magnetic anisotropy. Spin Hamiltonian.
2) Bistability and hysteresis in magnetic molecules. The process of inversion of the magnetization. Relaxation in the thermally activated and quantum tunneling regime. Perspectives and applications.
Gatteschi Sessoli Villain “Molecular Nanomagnets” Oxford University Press 2006 (available in the library)
Olivier Kahn “Molecular Magnetism” Wiley 1993 (available on request)
Learning Objectives
Students should acquire the following knowledge: Basic electronic structure of metal ions in condensed matter. Spin Hamiltonian in magnetic molecules. Techniques for characterizing the magnetic properties. Origin of magnetic anisotropy, modeling and controlling the spin dynamics.
At the end of the course the student should be able to recognize the systems and/or situations in which the analysis of magnetic properties can provide additional information on their electronic structure. The student should also be able to choose the best suited investigation technique among those studied in the course.
6 CFU
Standard lectures, participation to experiments in laboratories (hours): 48
Type of Assessment
It is possible to take the exam by performing a short practice in the laboratory of magnetism followed by an analysis of the data collected and the discussion of a short report prepared by the student.
Alternatively a standard exam based on questions of the subjects of the program can be chosen.
Course program
Part 1. 3 CFU
a) Magnetic interactions in molecular systems:
- electronic levels of the free ion
- group theory
- ligand field theory
b) The spin Hamiltonian formalism
- magnetic anisotropy
-exchange and dipolar interactions
Part 2 . 3 CFU
a) Investigation techniques in molecular magnetism
- dc magnetometry
- ac susceptometry
- electron paramagnetic resonance (EPR)
b) Magnetic bistability in molecular systems: Thermally activated regime; Tunneling regime; comparison with magnetic nanoparticles