Attaching Thiolated Superconductor Grains on Gold Surfaces for Nanoelectronics Applications

We report that the high critical temperature superconductor (HTCS) LaCaBaCu3O7 in the form of nanograins can be linked to Au(111) surfaces through self assembled monolayers (SAMs) of HS–C8H16–HS [octane (di)thiol]. We show that La1113 particles (100 nm mean diameter) can be functionalized by octane (di)thiol without affecting their superconducting critical temperature (T C=80 K). X-ray photoemission spectroscopy (XPS) analysis reveals that the thiol functional heads link the superconducting grain surfaces creating sulfonates and we deduce that bonding between the S atoms and Cu(1) atoms of the La1113 structure would be formed. We suggest a design for a superconducting transistor fabricated by immobilized La1113 nanograins in between two gold electrodes which could be controlled by an external magnetic field gate.