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Bonnie Ludka
James Madison University

Subject Listing - Physics/Astronomy
Advisor: Dr. David Schaefer

Friday, Poster Session 5, Presentation Kiosk 25 A, Health & Fitness Center

SURFACE MODIFICATION OF PEROVSKITE MANGANITE THIN FILMS USING ATOMIC FORCE MICROSCOPY

Nanolithography using the atomic force microscope (AFM) is emerging as a promising tool for nanotechnology . In this work, a commercial AFM was used to perform nano-oxidation of localized regions on silicon and manganite substrates. The oxidation patterns were controlled by a user written LabView program. We report our results of AFM- induced nanoscale surface modifications in thin films of the CMR manganite material La0.7Ba0.3MnO3. CMR manganite materials have been demonstrated to be useful for a variety of technological applications including magnetic sensors and bolometric infrared detectors. AFM induced surface modifications would enable the realization of such sensors in nanotechnology applications. We have obtained reproducible patterns on these films in the form of nanoscale dots and lines induced by the AFM tip. We have studied these feature dimensions as a function of tip bias voltage, exposure time and humidity. We find that the feature heights are considerably larger on manganite thin film surfaces than those induced on silicon surface under similar conditions. Additionally, the speed of reproducible writing is also found to be significantly higher on the manganite films. The application of these materials to nanoscale memory devices will be discussed.

Advisor: Dr. David Schaefer, Professor, Department of Physics, Astronomy, and Geosciences, Towson University, Towson, MD