Lorentz transmission electron microscopy and magnetic force microscopy characterization of NiFe/Al-oxide/Co films

Thumbnail Image
Date
2002-01-15
Authors
Yu, Andrew
Lo, Chester
Petford-Long, Amanda
Miyazaki, Terunobu
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
Jiles, David
Distinguished Professor Emeritus
Research Projects
Organizational Units
Organizational Unit
Materials Science and Engineering

The Department of Materials Science and Engineering teaches the composition, microstructure, and processing of materials as well as their properties, uses, and performance. These fields of research utilize technologies in metals, ceramics, polymers, composites, and electronic materials.

History
The Department of Materials Science and Engineering was formed in 1975 from the merger of the Department of Ceramics Engineering and the Department of Metallurgical Engineering.

Dates of Existence
1975-present

Related Units

Journal Issue
Is Version Of
Versions
Series
Abstract

Magnetization reversal process of NiFe/Al-oxide/Co junction films was observed directly using Lorentztransmission electron microscopy (LTEM) and magnetic force microscopy(MFM).In situmagnetizing experiments performed in both LTEM and MFM were facilitated by a pair of electromagnets, which were mounted on the sample stages. A two-stage magnetization reversal process for the junction film was clearly observed in LTEM with NiFe magnetization reversed first via domain wall motion followed by Co magnetization reversal via moment rotation and domain wall motion. Reversal mechanism and domain characteristics of the NiFe and Co layers showed very distinctive features. The magnetization curve of the junction filmmeasured using alternating gradient force magnetometry showed a nonzero slope at the antiparallel magnetization configuration region, which implies that magnetization directions of the NiFe and Co layers were not exactly antiparallel due to Co moment rotation existed in that region. After the magnetization reversal of the Co was complete, MFM images revealed some magnetic contrast, which suggests that an out-of-plane magnetization component remained in the Co layer. Such magnetic contrast disappeared at higher magnetic fields when the Co moments further rotated and aligned parallel to the applied field direction.

Comments

The following article appeared in Journal of Applied Physics 91 (2002): 780 and may be found at http://dx.doi.org/10.1063/1.1427142.

Description
Keywords
Citation
DOI
Copyright
Tue Jan 01 00:00:00 UTC 2002
Collections