Implantation, damage, and regrowth of high Tc superconductors
Abstract We have observed superconductivity in thin films of (La1−xSrx)2CuOy which are fabricated by implanting evaporated La/Cu multilayer films with Sr and annealing in oxygen. The films are insulating and partially transparent as-implanted, but they darken and become conducting at annealing temperatures as low as 500°C. The resistive behavior is very sensitive to the annealing conditions and the superconducting layer appears to be buried beneath the surface. Similarly, implantation of F, O, and Ne into single crystals and high quality (χmin
High energy ion beam mixing of ceramic-metal multilayers: La(OH)3/Sr(OH)2/Cu
Abstract We have studied ion beam mixing in multilayers of La(OH) 3 /Sr(OH) 2 /Cu, the components of which are of interest in new superconducting thin films with high transition temperatures. Information is given on the depth distributions of the different species, La, Sr, Cu, O and H, of the compounds formed under irradiation. The beam treatment resulted mainly in breaking of the LaOH and SrOH bonds, leading to hydrogen desorption, while new atomic bonds were formed between La, Sr, Cu and O atoms. Nearly no ballistic effects were observed, a situation very different from that seen in ion beam mixing of metallic multilayers.
Variation of superconductivity with carrier concentration in oxygen-doped YBa2Cu3O7-y.
The Hall coefficient R/sub H/, the volume fraction f showing the Meissner effect, and the superconducting transition temperature T/sub c/ have been measured in the high-T/sub c/ oxide YBa/sub 2/Cu/sub 3/O/sub 7-//sub y/ for a range of oxygen vacancy concentration 0.0