Abstract: A high-T.sub.c superconductor contact unit having low interface resistivity is disclosed, as is a method for making the unit. An inert metal is deposited on the surface of the superconductor, which surface is preferably non-degraded, to form a unit with the surface of the superconductor, and where temperatures as high as 500.degree. C. to 700.degree. C. can be tolerated, the unit is oxygen annealed to establish a still lower surface resistivity between the surface of the high-T.sub.c superconductor and the inert metal, including a low surface resistivity of about 10.sup.-10 .OMEGA.-cm.sup.2 at high-T.sub.c superconductor operating temperatures. The superconductor is a metal-oxide superconductor, and may be rare earth, thallium, or bismuth based.

Abstract: A tool consists of an array of field-emitting nanostructure probe tip extensions on the end of a metal probe. The probe is tapered to a long, narrow, flat end with typical dimensions of 1 cm.times.1 .mu.m. The probe tip extensions typically extend approximately 100 .ANG. beyond the probe surface and their ends are shaped to act as independent field-emission tips, each at an exact atomic location. These ends are a single crystal plane terminating in a single crystal unit plane cell having a central atom with a lower work function than the atoms surrounding the central atom. The nanostructures are spaced in a prescribed, repeating pattern with typical spacings on the order of 400 .ANG.. The probe voltage, current and position, as well as CVD or etching gas pressures, are sequentially adjusted to fabricate nanostructures on a nearby substrate, which is typically 10-30 .ANG. below the termination points of the probe tip extensions.

Abstract: A periodic scattering array is used to diffract electromagnetic radiation or massive particles of specific wavelength and energy. A detector sutiable to the radiation or particles is integrated into the surface or bulk of the array. The detector is configured so as to not perturb the diffraction resolution of the array.