AFM/STM asymmetry work on graphene has appeared on the cover of the May 2015 issue of the Journal of Vacuum Science & Technology B.
Graphene – a two-dimensional sheet of carbon atoms arranged in a honeycomb pattern – has received tremendous attention from the scientific community in the last decade due to its outstanding physical properties. The discovery of the so-called wonder material in 2004 by Profs. Andre Geim and Konstantin Novoselov at the University of Manchester has quickly resulted in a Nobel Prize in Physics.
Now, researchers at the Scanning Probe Microscopy (SPM) Research Group led by Asst. Prof. Mehmet Z. Baykara at the Department of Mechanical Engineering at Bilkent University have contributed to the atomic-scale understanding of this material, as documented in an article that has appeared on the cover of the May 2015 issue of the Journal of Vacuum Science & Technology B.
When asked about the motivation for the work, Prof. Baykara indicated that “despite its exceptional potential for practical applications, integration of graphene into functional devices requires a comprehensive understanding of its atomic-scale properties. Towards this goal, scanning probe microscopy has been utilized since the discovery of the material. However, experiments conducted by different research groups around the world often lead to conflicting results”.
Thanks to the work discussed in detail in the article, the culprit behind the experimental inconsistencies in the literature has been found: the probe. “Our work has demonstrated a clear dependence of atomic-scale SPM experiments on the physical properties of the probe itself – namely, asymmetry and elasticity”, indicated Asst. Prof. Mehmet Z. Baykara. “As such, we were able to shed light on a number of controversial results in the literature, and have provided experimentalists a guide with which they can check the accuracy of their results”.
Prof. Baykara further remarked that “a very important aspect of the work is that it has been performed with substantial contributions by an undergraduate student, Berkin Uluutku. At Bilkent Mechanical Engineering, we put great importance on the participation of successful undergraduates in research projects. Berkin has been supported by the 2209/A program of TUBITAK which is intended to foster undergraduate research at universities”.
At the Department of Mechanical Engineering at Bilkent University, 11 undergraduates have received TUBITAK undergraduate research awards during the last 3 years.
The cover article titled “Artifacts Related to Tip Asymmetry in High-Resolution Atomic Force Microscopy and Scanning Tunneling Microscopy Measurements of Graphitic Surfaces” can be reached here: http://dx.doi.org/10.1116/1.4915898