Abstract: High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La2CuO4) and a metal (La1?xSrxCuO4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, Tc may be either ˜15 K or ˜30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, Tc exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high Tc phases and to significantly enhance superconducting properties in other superconductors.

Abstract: High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La2CuO4) and a metal (La1?xSrxCuO4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, Tc may be either ˜15 K or ˜30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, Tc exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high Tc phases and to significantly enhance superconducting properties in other superconductors.

Abstract: A hybrid oxide heterostructure device is disclosed. The device includes a substrate, and formed monolithically on the substrate, by atomic layer-by-layer molecular-beam epitaxy, successive metal oxide layers forming a high-temperature superconducting (HTS) structure and a multi-layer magnetic memory/storage structure. The HTS structure includes one or more HTS metal oxide layers formed on the substrate, and electrical contacts formed on the one or more HTS layers. The magnetic-memory structure includes one or more metal oxide magnetic layers formed monolithically on, below, or between the layer(s) of the HTS device, and having electrical contacts formed on one or more of the magnetic layers. Application of current or voltage to an HTS structure, under conditions effective to establish a superconducting current in the HTS structure, is effective to alter read or write characteristics of the memory-storage structure.

Abstract: An apparatus and a method is disclosed for in-situ deposition of thin films of high-temperature superconductor (HTS) compounds on a substrate that involves exposure of the substrate to a high pressure of oxygen and/or a high vapor pressure of volatile metallic elements such as Hg, Tl, Pb, Bi, K, Rb, etc., for stabilization of the crystal structure. Such compounds include basically all known HTS materials with Tc higher than 100 K. The method is based on pulsed laser deposition (PLD) and a cyclic (periodic) process, wherein the substrate is shuttled between a “closed” and an “open” position. In the “closed” position it is exposed to high temperature and high pressure of oxygen and/or volatile metallic species. In the “open” position, it is kept under low pressure and exposed to PLD plume. Short deposition bursts occur while the substrate is in the open position.

Abstract: A thin-film of a high temperature superconducting compound having the formula M1-xCuO2-y, where M is Ca, Sr, or Ba, or combinations thereof, x is 0.05 to 0.3, and x>y. The thin film has a Tc (zero resistivity) of about 40 K. Also disclosed is a method of producing the superconducting thin film.

Abstract: A thin film which is substantially free of measurable surface defects due to second-phase inclusions is disclosed. The film is composed of multilayered strata of a first metal oxide interspersed with single molecular layers of a second metal oxide, where the second metal oxide is effective to absorb second-phase defects which form in the first oxide layers.

Abstract: A hysteretic high-T.sub.c trilayer Josephson junction, and a method of forming the same are disclosed. The junction includes lower and upper high T.sub.c superconducting cuprate films separated by a barrier layer, where the thin films each include a molecular junction layer adjacent the barrier layer which is characterized by a high-T.sub.c cuprate stoichiometry and crystal structure, and a flat two-dimensional surface, as evidenced by its electron diffraction pattern using reflected high-energy electron diffraction. The junction and barrier layers in the junction are formed by atomic layer-by-layer deposition.

Abstract: A new method for accurately and sequentially growing monolayers and creating new superlattice structures employing a MBE thermal source control technique employing a quasi-double beam atomic absorption background correction measurements with the beam blocked and with the beam unblocked and by calculating the concentration based on the: ##EQU1## and applying corrections for non-linear absorption curves because of comparable spectral bandwidth of the molecular beam.

Abstract: Compounds of the formula Bi.sub.1 Sr.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.