Nanoscale & Magnetism - PHY00043H

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  • Department: Physics
  • Module co-ordinator: Dr. Steve Tear
  • Credit value: 20 credits
  • Credit level: H
  • Academic year of delivery: 2019-20
    • See module specification for other years: 2018-19

Related modules

Co-requisite modules

  • None

Prohibited combinations

  • None

Module will run

Occurrence Teaching cycle
A Autumn Term 2019-20 to Spring Term 2019-20

Module aims

This module aims to give students a working understanding of the physics and terminology of magnetism, magnetic materials, and techniques for investigating materials on the nanoscale.

The magnetism course aims to present an understanding of the origins of diamagnetism, paramagnetism and ferromagnetism and the consequences in particular of ferromagnetism for the behaviour of bulk materials based on a simple description of domain theory. To understand the importance of single domain particles and how their behaviour is controlled and in particular the role of thermal energy in creating disorder at the nanoscale. To have an understanding of the operation of technological applications such as magnetic recording, permanent magnets and soft magnetic materials.

Analysing the Nanoscale course presents an overview to the current interest and challenges in the burgeoning area of nanoscience and nanotechnology, and introduces you to some of the state-of-the-art techniques required to characterise materials on the nanoscale. Nanoscience and nanotechnology is defined as relating to the study and creation of structures which have dimensions of less than 100 nanometres. This course will focus on two main themes:

(i) understanding some of the properties of solid materials when dimensions are reduced to nanometre length scales; and

(ii) the principles underlying, and application of, some key characterisation and analysis instruments and techniques which enable the study of solid materials on the nano to atomic scale.

Module learning outcomes

At the end of this module successful students will be able to:

  • Discuss some of the motivations, benefits and challenges which arise when the dimensions of structures become <100nm.
  • Describe the role and significance of crystalline surfaces and interfaces in nanostructures. Explain the use and merits of electrons to probe surfaces.
  • Explain, and have some quantitative understanding of, some of the basic elastic and inelastic interactions of energetic electrons with solids.
  • Explain the principal operation of the SEM, and the physics, some quantitatively, underpinning the SEM.
  • Outline the advantages and limitations of SEM for surfaces and nanostructures analysis.
  • Explain the principal operation of the instruments and different imaging modes of STM and AFM, and the physics, some quantitatively, underpinning the STM and AFM.
  • Outline the advantages and limitations of STM & AFM for surfaces and nanostructures analysis.
  • Describe some applications of STM, AFM and SEM analysis to materials surfaces.
  • Discuss the use of spectroscopic techniques, Auger electron, electron energy loss, X-ray photoelectron spectroscopy, and X-ray microanalysis to study surfaces, their merits and limitations.
  • Explain why surface and nanoparticle properties can be significantly different to the bulk and in some cases in what way.
  • Describe the processes of interface formation and epitaxial growth at an atomistic level.
  • Explain the principal operation of the TEM and STEM, and the physics, some quantitatively, underpinning the TEM/STEM, and have some quantitative understanding of the imaging modes
  • Discuss the advantages and limitations of TEM/STEM for nanostructure analysis.
  • Describe some applications of TEM in the analysis of nanostructures.
  • A review of the definitions and concepts of magnetism such as flux, flux density and field. Review of units to include the normally used CGS system.
  • Review of ordered magnetism and the role of direct and indirect exchange. Relationship to Curie temperature and Néel temperature.
  • Band theory of ferromagnetism and itinerant ferromagnetism.
  • The concept of the demagnetising field and its role in magnetisation reversal processes.
  • Concept of magnetic anisotropy in terms of crystalline and shape effects and in particular perpendicular anisotropy.
  • Formation of domains, domain walls and hysteresis in bulk materials. The role of the demagnetising field.
  • The origin and concept of single domain materials and reversal via the Stoner Wohlfarth mechanism.
  • Thermal activation and superparamagnetism. Magnetic viscosity and implications for stability e.g. in data storage.
  • Principles of magnetic recording in particular storage perpendicular to the plane.
  • Concept of GMR and TMR (phenomenology only). Design of stacks for GMR and TMR heads.
  • Magnetic recording discs, ECC media and heat assisted magnetic recording.
  • Soft magnetic materials, energy losses and applications.
  • Permanent magnets, operating point, reversal in NdFeB, hybrid systems.

Module content

Please note, students who have not taken the prerequisites listed above must have taken an equivalent version of Thermodynamics and Solid State II and Mathematics II.


Analysing the Nanoscale

1. Introduction to nanotechnology

  • An overview of nanotechnology.
  • Several examples given to illustrate the broad nature of nanotechnology. The benefits and the challenges in materials and electronics as dimensions get smaller.

2. Fundamental & technological interest in surfaces and interfaces

  • Motivation for studying surfaces and interfaces. Relationship to nanotechnology.
  • Crystal surfaces, nanoparticles and their properties, microstructure.
    • Role of surfaces in heterogeneous interface formation. Ultra high vacuum

3. Sensitivity of different probes for nanoscale analysis of solid materials

  • Overview of limitations and advantages of different probes for nanoscale analysis: atoms, ions, photons, and electrons
  • Interaction and detection of scattered electrons from solids: elastic and inelastic mean free path, attenuation length, elastic scattering cross section, stopping power.

4. Spectroscopy

  • Spectroscopic techniques: electron spectroscopy, loss spectroscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy, x-ray microanalysis
  • Examples of applications

5. Imaging and analysing surfaces: the SEM

  • Scanning electron microscopy: principles of instrument, secondary electrons, backscattered electrons, imaging modes,
  • Interaction volume and dependence on incident electron energy.
  • Sampling volume and dependence of electron detection energy.
  • Limitations and advantages of SEM. Spatial resolution.
  • X-ray microanalysis in the SEM: principles, spatial resolution, thin-film analysis.
  • Examples of applications

6. Imaging and analysing surfaces: the STM

  • Scanning tunnelling microscopy: principles, imagine modes, true local probe for analysis of nanostructures with atomic resolution. Pros and cons.
  • Scanning tunnelling spectroscopy: relationship to local density of states.
  • Examples of application to semiconductor and metallic surfaces.

7. Imaging and analysing surfaces: the AFM

  • Principles of AFM: imaging modes: contact, intermittent and non-contact. Atomic resolution in non-contact modes. Discussion of other scanning probe techniques, e.g. magnetic force microscope, force probes
  • Examples of applications: insulator surface, biophysics

8. Imaging and analysing nanoparticles and interfaces: the TEM and STEM

  • Principles of TEM and STEM instruments: imaging modes, spectroscopy, specimen requirements
  • Limitations and advantages of TEM/STEM for nanostructure analysis, spatial resolution, aberration correction.
  • X-ray microanalysis in the TEM/STEM
  • Examples of applications


1. Origin and properties associated with diamagnetism and paramagnetism.

2. Ferromagnetism - Curie-Weiss Law, Molecular field, exchange interactions

3. Domain Theory - Demag field, Ems, Domains and walls, Anisotropy – cubic and uniaxial

4. Single Domain Particles – Origin, Stoner-Wohlfarth Model

5. Hysteresis and Thermal Effects - Remanence and Coercivity, SFD, Superparamagnetism

6. Thin Film Magnetism - Thin film growth, Properties, GMR

7. Magnetic Recording – Principles, Disc, Head

8. Permanent Magnets - Basis, BHmax, Nd Fe B

9. Soft Materials – Types, Sources of Loss, Materials and Applications


Task Length % of module mark
Magnetism Assignment
N/A 7
Nanoscale PPQs
N/A 7
University - closed examination
Nanoscale & Magnetism
3 hours 86

Special assessment rules



Task Length % of module mark
University - closed examination
Nanoscale & Magnetism
3 hours 86

Module feedback

Physics Practice Questions (PPQs) - You will receive the marked scripts via your pigeon holes. Feedback solutions will be provided on the VLE or by other equivalent means from your lecturer. As feedback solutions are provided, normally detailed comments will not be written on your returned work, although markers will indicate where you have lost marks or made mistakes. You should use your returned scripts in conjunction with the feedback solutions.

Exams - You will receive the marks for the individual exams from eVision. Detailed model answers will be provided on the intranet. You should discuss your performance with your supervisor.

Advice on academic progress - Individual meetings with supervisor will take place where you can discuss your academic progress in detail.

Assignments - Feedback on assignments will be returned within four weeks of the assignment deadline.

Indicative reading

Jiles D: Introduction to Magnetism and Magnetic Materials 2nd Ed (Chapman & Hall)

Cullity B D and C Graham: An Introduction to Magnetic Materials. IEEE Press

Peter J. Goodhew, John Humphreys, Richard Beanland: Electron microscopy and analysis. Taylor & Francis, 3rd edn. **

M Prutton: Introduction to Surface Physics. OUP **

Charles P. Poole, Jr., Frank J. Owens: Introduction to nanotechnology. Wiley.*

Ashcroft N W & Mermin N D: Solid state physics (Saunders College) **

The information on this page is indicative of the module that is currently on offer. The University is constantly exploring ways to enhance and improve its degree programmes and therefore reserves the right to make variations to the content and method of delivery of modules, and to discontinue modules, if such action is reasonably considered to be necessary by the University. Where appropriate, the University will notify and consult with affected students in advance about any changes that are required in line with the University's policy on the Approval of Modifications to Existing Taught Programmes of Study.