Micropatterning of Samples for Scanning Probe Microscopy Measurements

S. Urazhdin, S.H. Tessmer and Norman. O. Birge

Department of Physics and Astronomy
Center for Fundamental Materials Research
Michigan State University

Experiments show that the grain boundaries (GB) in high temperature superconductors act as weak links between the crystalline gains and this results in greatly reduced critical current in polycrystalline wires used in applications. Our study is directed towards better understanding of the physics of the GB layer. Fig. a) is an optical micrograph of a system of gold arrows lithographically deposited on the surface of YBCO (high temperature superconductor) sample with a GB. We use this pattern to find the GB feature. Fig. b) is an STM topographical image of the GB area showing a slight depression in topography along the GB line with inset showing the meandering. In our study we are looking at the quasiparticle density of states as well as charging properties of the GB