Surface Modification of CMR Perovskite Manganite Thin Films using Atomic Force Microscopy

Nanolithography using the atomic force microscope (AFM) is emerging as a promising tool for nanotechnology . We report our results of AFM- induced nanoscale surface modifications in thin films of the CMR manganite material La$_{0.7}$Ba$_{0.3}$MnO$_{3}$. 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.