Magnetic and Electronic Measurement Techniques

In this module an introcuction into the physics and technology of modern magnetic and electronic measurement techniques is given. Following a repetition of some basics, the generation of magnetic fields in the laboratory is discussed. In the main part of the lecture, different measurement techniques are introduced in context with relevant scientific questions. These questions address the experimental determination of, e.g., Fermi surfaces using torque magnetometry, the specific heat of bulk samples, domain structures in magnetic recording media using Magnetic Force Microscopy, magnetization dynamics using the magneto-optical Kerr effect or the arrangement of atomic magnetic moments on solid-state surfaces detected by spin-polarized scanning tunneling microscopy. The underlying physical principles and the technological realizations of the measurement methods are highlighted. The physics of the phenonema under investigation as well as the physics of the relevant measurement technique are discussed with a focus on the basic physical aspects in this area of experimental physics. Current scientific developments in these topical area are considered in this module.

After successful participation in this module the student is able to:

1. understand and explain different concepts of magnetic systems and the effects of magnetic fields on different solid-state systems;
2. understand and explain the physical aspects of specific laboratory measurement techniques, in particular the interaction between measurement object and sensor;
3. describe and explain the technical implementation of different measurement techniques;
4. judge the spatial and temporal resolution capability of measurement techniques.;
5. select and to sketch experimental setups relevant for the investigation of physical questions in magnetism and electronic structure;
6. name the different time- and length scales relevant to magnetic and electronic phenomena.

No preconditions in addition to the requirements for the Master’s program in Physics.

The module consists of a lecture series and lab tours. The lectures are beamer presentations using PowerPoint-slides for visualization and detailed hand written text using digital ink. This mixture is intended to give a fast overview over facts and experiments on the one hand and the adaptation of the lecture speed to the speed of the students. Selected short „home work“ exercises with direct and deepening context will be discussed during the following lecture. The time frame of the lecture allows for dynamic interaction and detailed answers to questions. The resulting scientific discussions actively engage the students.

The lectures are complemented by lab tours. The lab tours will take place by arrangement oriented on the lab work. The predominant part of the measurement techniques discussed are used in the research conducted at the physics department such that we have access to a broad spectrum. The focus of each individual lab tour is oriented on the current status of the experimental facility. For example, an experiment under reconstruction often allows access to the technological implementation while a visit to an important running experiment would focus more on the magnetic systems under investigation.

The interplay of presentation slides für overview and details, hand written text for solid foundations and lab tours for direct relation to practice enables the students to acquire the above formulated competences with regard to the physics and technology of magnetic measurement techniques.

lecture script with slides and hand-written text, accompanying internet site, complementary literature

1. Kronmüller H., Parkin S.S.P. (Eds.): Handbook of Magnetism and Advanced Magnetic Materials, Vols. 1-5 (Wiley, Chichester, 2007)
2. Getzlaff, Matthias: Fundamentals of Magnetism (Springer Verlag, 2008)
3. Zhu, Yimei: Modern techniques for characterizing magnetic materials (Springer New York, 2005)
4. Ashcroft, Mermin: Solid State Physics (Saunders, 1988)

There will be an oral exam of 25 minutes duration. Therein the achievement of the competencies given in section learning outcome is tested exemplarily at least to the given cognition level using comprehension questions and sample calculations.

For example an assignment in the exam might be:

• Name different magnet designs and discuss their merits and limitations
• Discuss the physical mechanisms underlying the concept of magnetic force microscopy
• Rank the spatial and temporal resolution of the magnetic measurement techniques discussed in the lecture
• Outline the specific technical implementation of a magnetic measurement technique discussed in the lecture