APPLIED PHYSICS LETTERS, cilt.91, 2007 (SCI İndekslerine Giren Dergi)
Superconducting niobium nitride wires and ribbons with transverse dimensions down to tens of nanometers were synthesized by annealing NbSe3 nanostructure precursors in flowing ammonia gas at temperatures up to 1000 degrees C. Their critical temperatures increase with increasing annealing temperatures and reach 9-11.2 K when sintered at 950 degrees C or above. X-ray diffraction analyses identified Nb4N5 and Nb5N6 phases, dominating at annealing temperatures below and above 950 degrees C, respectively. Transport measurements show magnetoresistance oscillations at temperatures near the superconducting transition due to vortex-row confinement effects and voltage jumps in current-voltage characteristics at low temperatures attributed to hot-spot behavior. (C) 2007 American Institute of Physics.