Jump to ContentJump to Main Navigation
Fundamentals and Applications of Magnetic Materials$
Users without a subscription are not able to see the full content.

Kannan M. Krishnan

Print publication date: 2016

Print ISBN-13: 9780199570447

Published to Oxford Scholarship Online: December 2016

DOI: 10.1093/acprof:oso/9780199570447.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (oxford.universitypressscholarship.com). (c) Copyright Oxford University Press, 2020. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in OSO for personal use. date: 24 November 2020

Fine Particles and Nanostructured Materials

Fine Particles and Nanostructured Materials

(p.358) 9 Fine Particles and Nanostructured Materials
Fundamentals and Applications of Magnetic Materials

Kannan M. Krishnan

Oxford University Press

In this chapter, we discuss fundamental aspects of the magnetic behavior of fine particles and nanostructured materials, with emphasis on magnetic reversal, surface, finite size, and interaction effects. Energy barrier distributions and thermal excitations as a function of temperature and measurement time gives rise to superparamagnetism in fine particles below a characteristic size, or above a characteristic blocking temperature. The concept of magnetic viscosity, which maps the energy barrier distribution as well as the behavior of ferrofluids, including their field-dependent viscosity or magnetoviscosity is introduced. Time dependence of magnetization and their dynamics or response to an applied ac field, including the in-phase and loss components are described. Related experimental methods that are specific to determining their magnetic characteristics and the theoretical models used to interpret them are presented. These include Chantrell fitting of magnetization measurements to obtain nanoparticle size distributions, field-cooled and zero-field-cooled measurements, various remanence measurements to determine interactions, and Mössbauer spectroscopy. Some of the basic principles presented here will be further developed in later chapters that deal with specific applications in hard and soft magnets (§11), medicine and biology (§12), and information storage (§14).

Keywords:   magnetization reversals, superparamagnetism, blocking temperature, ZFC & FC measurements, magnetization dynamics, finite size and surface effects, ferrofluids, Mössbauer spectroscopy

Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us .