Investigators: R. D. McMichael, L. H. Bennett, H. J. Brown, R. Drew, D. Mathews, R. Shull

Technical Description:

In this project, a variety of electrical and magnetic techniques are developed for and applied to the characterization of multilayered nanoscale films, especially magnetic multilayers. An emphasis has been on the identification of processes involved in degradation of the multilayer structures at moderately elevated temperatures.

Technical Objectives:

• Develop electrical and magnetic test methods and magnetic imaging techniques needed to characterize multilayer nanoscale films.

• Develop computational micromagnetic modeling techniques for comparison with experimental results.

• Collect data on the effects of thermally induced damage to nanoscale film structures, and compare with model results.

• Organize workshops to bring the micromagnetic modeling community to consensus on recommended modeling procedures.

Anticipated Outcome:

• Identification of mechanisms for thermal degradation of nanoscale multilayers.

• Reliable nondestructive imaging techniques and electrical and magnetic characterization methods for nanoscale multilayers.

• Improved accuracy and speed in computational micromagnetic modeling.

Accomplishments for FY 1995:

• NIST/Center for Theoretical Computational Materials Science (CTCMS) sponsored workshop on micromagnetic modeling with representatives from academia and industry identified opportunities and challenges in micromagnetic modeling.

• Used superconducting quantum interference device (SQUID) magnetometry, magnetoresistance and ferromagnetic resonance techniques to identify the "weak link" in annealed spin valves. Changes based on this information resulted in improved thermal stability of these structures.

• Identified magnetization reversal mechanisms and magnetic domain structures by optical and scanning probe techniques.

• Wrote computer programs for micromagnetic modeling. This code may become the basis for a public distribution.

Impacts and Technical Highlights:

• Measurement of the temperature stability of the thin films used in multilayers provides critical data about how well the layers will hold up running at elevated temperatures in devices.

Back to Table of Contents

Last modified: Mon Jan 06 09:46:15 1997 Metallurgy Webmeister