OVERVIEW

This course examines the transport and magnetic properties of different classes of advanced materials.
Particular attention is devoted to the physical mechanisms that determine their electrical, thermal, and magnetic behavior.
The course provides the theoretical background needed to understand how microscopic processes influence macroscopic properties.
Examples will include materials of technological interest and their relevance for modern  applications.
Some simple semiconductor devices will also be studied, with emphasis on their operating principles and physical interpretation.

AIMS AND CONTENT

LEARNING OUTCOMES

To understand the physical processes ruling the thermal and electric transport and the magnetic properties in advanced materials. To identify the key properties to be used for the choice of materials in specific applications. To learn experimental methods to characterise relevant magnetic and transport properties.

AIMS AND LEARNING OUTCOMES

To understand the physical processes ruling the magnetic properties in materials: role of the electronic structure, of the crystal field and of the exchange integral in determining the magnetic state at different temperatures

To be able to identify the key parameters that determine the magnetic response of a material and to use this information to select the material for specific applications in particular with respect to soft and hard ferromagnets.

To be able to  measure the magnetization hysteresis curve of a ferromagnet.

To understand the influence on the transport properties of multiband electronic structures and low dimensionality.

To understand how the electronic band structure and the relevant scattering channels influence the transport properties of materials, and  possible strategies to engineer such properties for specific functional applications.

To understand physical operation mechanisms of common electronic devices.

To be able to identify the correlation between material properties and device performances.  

To understand principles and peculiarities of spin polarized transport in materials and devices

To be able to write a concise but fully understandable reports about the experimental activity with clear presentation of the experimental data with their errors.

PREREQUISITES

Although there are no formal prerequisite requirements, students are strongly encouraged to have attended the first-semester courses, particularly Metals, Insulators and Semiconductors.

TEACHING METHODS

Oral lessons with presentation of the theoretical topics.

Demonstration with active role of the students in laboratory for the practical activities.

SYLLABUS/CONTENT

Theory (56 hours):

• Magnetic states of matter

Phenomenological classification of materials with respect to magnetic properties, Definition of magnetic moment, Torque acting on a magnetic moment, Summary on vectors B, H, and M, Notes on the vector potential, Hamiltonian of an atom in an external magnetic field, Diamagnetism. Quantum treatment, Larmor precession, Paramagnetism. Classical treatment and notes on quantum treatment, Magnetic moment of an atom and an ion: Hund's rules, Magnetic moment of 3d and 4f ions, Effect of the crystal field on the order of level fillings, Introduction to ferromagnetism, Introduction to the exchange integral: wave function of two electrons. Singlet and triplet states, Types of magnetic ordering: antiferromagnetic, ferrimagnetic, helical ordering, Easy and hard magnetization axes, Magnetocrystalline anisotropy energy, Estimate of domain wall size, Note on magnetostriction, Hysteresis loop: coercive field, residual magnetization, saturation magnetization, Soft and hard ferromagnets and examples of their applications, Pauli paramagnetism.

• Electrical, thermal and thermoelectrical transport properties in advanced materials.

Electrical, thermal, and thermoelectric transport properties in metals and semiconductors (resumé)
Effects of band structure on transport properties -Electrical, thermal, and thermoelectric transport in multiple bands materials
Scattering mechanisms in advanced materials: electron- phonon scattering, electron-magnon scattering and electron electron scattering. Scattering from grain boundaries and point defects
Temperature dependence of transport properties - Bloch Gruneisen law -Transport properties in advanced materials: two-dimensional materials and superconductors
Transport properties in p-n junctions and metal-insulator-semiconductor junctions.

• Applications in spin-electronics (basics)

Spin polarised transport, polarization and depolarization mechanisms, examples of spintronic devices

Lab (12 hours):
Three experimental activities selected among the following

• Transport in semiconductors: hall effect in doped semiconductors
• Transport in semiconductors: minority carrier diffusion (Haynes–Shockley)
• Magnetization of ferromagnetic materials
• Resistivity and magnetoresistivity in quantum materials
  • 2D materials
  • superconductors

RECOMMENDED READING/BIBLIOGRAPHY

S. Blundell: Magnetism in Condensed Matter Oxford University Press

K.Brennan: The Physics of Semiconductors - With Applications to Optoelectronic Devices

Slides used for the lessons.

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

According to the timetable reported here 

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

The exams will consists of:

1. brief discussion of  one of the experimental reports written by small group of students after each experimental activity and provided at least ten days before the exam.
2. Answer to two questions on the syllabus.

ASSESSMENT METHODS

The degree of achievement of the learning outcomes will be determined considering:

1. The completeness and readability of the reports on the experimental activity.
2. The degree of understanding demonstrated in answering the questions during the oral exam.
3. The capability to use the acquired knowledge to select materials for specific applications during the oral exam.
   
   Each part will contribute for 1/3 to the final score.

FURTHER INFORMATION

Students with disabilities and SLDs: Students with disabilities or specific learning disorders (SLDs) may request exam accommodations. The relevant certification must be uploaded to the University website at servizionline.unige.it, in the “Students” section. The documentation will be checked by the University Office for the Inclusion of Students with Disabilities and SLDs (https://rubrica.unige.it/strutture/struttura/100111). Subsequently, well in advance of the exam date, at least 7 days before, students must complete the dedicated online form (https://modulionline.unige.it/richiesta-adattamenti#no-back).

For further information on how to request services and accommodations, please consult: https://unige.it/disabilita-dsa/richiesta-servizi.