THIN FILM HG-BASED SUPERCONDUCTORS, THERMOELECTRIC MATERIALSAND METHODS OF FABRICATION THEREOF

摘要

Improved Hg-containing superconducting films and thermoelectric materials ar e provided. The films are fabricated by annealing starting T1-containing films (e.g., T1-1212 or T1-2212) in an Hg-vapor environment so as to cause a substitution of T1 by Hg without substantial alteration of the crystalline structure of the starting films. Preferably, a body comprising a substrate having an epitaxial T1-containing film thereon is annealed under vacuum conditions with a Hg-based bulk; typical annealing conditions are 600-900 ~C for a period of from about 1-20 hours. The final Hg-containing film products have a Jc of at least about 106 A/cm2 (100 K, OT) and a Xmin of up to about 50 %. The thermoelectric materials are prepared by perturbing a crystalline precursor having a structure similar to the final material so as to cause a first molecule to be released from the precursor. A vapor is introduced into the reaction system simultaneous to or shortly after the perturbation step s o as to cause molecules which are within the vapor and are different than the first molecules to replace the first molecules in the precursor.