This course focuses on the fundamentals of magnetism, and covers the application of magnetic materials in electronic devices.
Magnetic materials consist of magnetic moments and the relative orientation of the magnetic moments leads to a variety of magnetic ordering. This course begins with a brief introduction of electrodynamics and quantum mechanics, and introduce the origin of a magnetic moment. The course enables students to understand and acquire the fundamental approach to describing magnetic interactions between magnetic moments and the behaviors of magnetic moments in a crystal. Topics also include magnetic anisotropy, magnetization processes, magnetic domain structures, and magnetic resonance, providing a basis for applying magnetic materials to electronic devices.
By the end of this course, students will be able to:
1) Understand the concepts of magnetic moments, angular momentum, exchange interaction, etc. based on fundamentals of electrodynamics and quantum mechanics.
2) Understand the macroscopic magnetic properties of materials, including paramagnetism and ferromagnetism.
3) Understand magnetic phenomena in ferromagnetic materials (magnetic anisotropy, magnetization process, magnetic domain structure, magnetic resonance).
4) Understand the fundamental approaches to applying magnetic materials to device applications.
Electrodynamics, quantum mechanics, Schrödinger equation, magnetic moment, angular momentum, crystalline field, multiplet, Curie’s law, exchange interaction, Curie-Weiss law, Pauli paramagnetism, Slater-Pauling curve, magnetic anisotropy, magnetization process, magnetic domain structure, magnetic resonance, magnetotransport, applications of magnetism
|✔ Specialist skills||Intercultural skills||Communication skills||Critical thinking skills||✔ Practical and/or problem-solving skills|
To get a good understanding of the course contents, exercise problems are provided.
|Course schedule||Required learning|
|Class 1||Electrodynamics and magnetic moment||Derive the relationship between magnetic moment and ring current. Derive the equation representing the energy of a magnetic moment in a magnetic field.|
|Class 2||Quantum mechanics and Schrödinger equation||Understand the solution of Schrödinger equation in spherical symmetry.|
|Class 3||Angular momentum and construction of total angular momentum||Derive angular momentum in quantum mechanics.|
|Class 4||Crystalline field and quench of orbital angular momentum||Understand an energy shift of 3d states in octahedral crystalline symmetry and the mechanism of quench of orbital angular momentum|
|Class 5||Angular momentum of an atom and multiplets||Construct the total angular momentum of 2 p electrons.|
|Class 6||Free ion and Curie's law||Derive the Curie's law of a paramagnet.|
|Class 7||Exchange interaction and Curie-Weiss law||Derive the Curie-Weiss law based on exchange interaction.|
|Class 8||Band theory and Pauli paramagnetism||Derive Pauli paramagnetic susceptibility.|
|Class 9||Ferromagnetism in metals and Slater-Pauling curve||Derive the magnetic moment of an alloy|
|Class 10||Magnetic anisotropy||Derive the expression of uniaxial magnetic anisotropy in a polar coordinate system|
|Class 11||Magnetization process||Derive the magnetization curve of a uniaxial ferromagnetic particle.|
|Class 12||Magnetic domain structure||Derive the width of a domain wall and a domain wall energy|
|Class 13||Magnetic resonance||Derive the equation representing the precession of magnetization and dispersion relation.|
|Class 14||Magnetotransport||Understand the mechanisms of giant magnetoresistance and tunnel magnetoresistance.|
|Class 15||Applications of magnetism||Understand the mechanisms of some magnetic device applications|
Keizo Ohta. Fundamentals of Magnetics. Kyoritsu-shuppan; ISBN 4320002008, 9784320002005.
Soshin Chikazumi. Physics of Ferromagnetism. Oxford University Press; ISBN 0-19-851776-9.
Student's knowledge of fundamentals of magnetism and their ability to apply them to magnetic devices will be assessed. Evaluated by reports and a final exam.
Students must have successfully completed a class of electrodynamics or have equivalent knowledge.