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Laurie Stephey

University: Rollins College
Major: Physics
Gradation Date: May 2009
Hometown: Winter Park, Florida

Project:  In 2008, Hewlett-Packard reported that it had fabricated a memory device with properties consistent with a theoretical device postulated in 1971 called a memristor. At NIST, Dr. Nadine Gergel-Hackett has been working to fabricate similar devices using economical and simple fabrication techniques. However, the devices in the study were relatively large, of lower than desirable reliability, and the physics which governed their behavior were poorly understood. The goal of this project was to remedy some and possibly of all of these issues.

Two sizes of flexible devices have been fabricated (2 millimeter by 2 millimeter and 100 micron by 100 micron). Several thicknesses of the insulating material have been used to fabricate both device sizes, and the impact of changing insulator film thickness in the devices has been studied. By decreasing film thickness, the 100 micron devices were fabricated to switch at significantly lower bias. Parameters including charge magnitude, current magnitude, bias magnitude, and resistance have been investigated to search for potential trends in switching behavior. Preliminary analysis indicates that charge magnitude may be a contributing factor to switching and also that switching mechanisms may display some area-dependence. Work is ongoing to fabricate more devices and analyze more data.

About me: As a child, my favorite place in the world was the Orlando Science Center, so it seemed inevitable that I would become a scientist. I was very fortunate to attend Rollins College, a school with a large emphasis on undergraduate research. There, I spent four summers working on two projects: the physics of the American five-string banjo and using atomic layer deposition (ALD) to alter the optical properties of photonic crystal fibers. I really enjoyed all of my research experiences (especially my time here at NIST), and I intend to continue on my path towards becoming a scientist.

I am not actually a SURF student; I am here at NIST as a Society of Physics Students intern. However, I have been doing my best to make the best of all the opportunities provided by the SURF program. I have enjoyed getting to know the other SURF students and attending the weekly SURF seminars (all of which have been fantastic). I am very grateful that they have welcomed me in all their activities.

I am serving as a Water Quality Intern in CAC Americorps in Knoxville, TN, for the next year. Afterwards, I am currently planning to attend graduate school in Oceanography. I hope to do field research and eventually teach either at the high school or college level.


Laurie Stephey