Tuesday, May 21th, 2013
Western Digital, 1710 Automation Parkway, San Jose, CA
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Cookies, Conversation &
Pizza too at 6:45 P.M.
Presentation at 7:30 P.M.
Magneto-Optic Analysis of Magnetic Microstructures
Dr. Rudolf Schaefer
IEEE Distinguished Lecturer
Leibniz Institute for Solid State and Materials Research (IFW), Dresden, Germany
Abstract
The rich world of magnetic microstructure or magnetic domains, extending
from visible dimensions down to the nano-scale, forms the mesoscopic link
between the fundamental physical properties of a magnetic material and its
macroscopic properties and technical applications, which range from films
for computer storage technology to magnetic cores for electrical
machinery. Hysteresis phenomena, energy loss in inductive devices, noise
in sensors, or the magnetoresistive properties of modern spintronic
devices can be decisively determined by the peculiarities of the
underlying magnetic microstructure, especially by irreversibilities in the
magnetization process. Therefore any development and optimization of
magnetic materials, which is usually accompanied by the measurement of
magnetization curves, requires an understanding of the underlying domains
and their reaction to magnetic fields, which, in most cases, can only be
gained by direct imaging.
The presentation will address different
aspects of magnetic microstructure adapted, where possible, to the
interest of the audience and supported by domain observation using Kerr
microscopy. This may include domains and magnetization processes in bulk
magnetic material like oriented and non-oriented electrical steel,
amorphous and nanocrystalline ribbons or permanent magnets, as well as
thin films and multilayers. Fast magnetization processes can also be
considered. Most challenging is the analysis of hidden (internal) domains
and processes in bulk material. They are relevant for material performance
and their analysis requires surface imaging in combination with domain
modeling and some volume-sensitive imaging method. Aside from their
scientific and technical relevance, magnetic microstructures are also
aesthetically appealing, an aspect that will be part of the presentation.
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