METHOD AND APPARATUS FOR FABRICATION OF THIN FILM SUPERCONDUCTOR BY SPRAY PYROLYSIS CHEMICAL VAPOR DEPOSITION METHOD

摘要

Disclosed herein is a method and apparatus for fabrication of a thin film superconductor. Specifically, provided is a method and apparatus for fabrication of a thin film superconductor using spray pyrolysis chemical vapor deposition, comprising dissolving an inorganometallic compound as a raw material in distilled water to prepare a precursor solution, spraying the resulting precursor solution in a state of fine droplets, and coating an epitaxial thin film on a substrate (such as a ceramic material, a nickel metal, a nickel alloy, stainless steel or the like) via a pyrolysis process. The method comprises dissolving an inorganometallic compound having a water-solubility in distilled water to prepare a precursor solution; processing the precursor solution into droplets having a size of several μm to several tens of μm and storing the droplets in a raw material storage; transferring the droplets in the storage to a main pipe via a pump and simultaneously supplying the droplets, in conjunction with carrier and reactant gases supplied by operation of a valve, to a nozzle; heating the droplets sprayed from the nozzle by an auxiliary heat source to evaporate the distilled water, thereby preparing fine-sized particles of the inorganometallic compound; elevating a temperature of a heater formed in a table, such that the resulting particles react with the reactant gas to form an oxide; uniformly forming a film of the oxide at opposite sides on a single crystal substrate having a certain texture provided to the table via conveyers, by a ∧ shaped stainless steel plate, thereby forming an oxide template having a certain texture on the upper part of the substrate, and sufficiently heating the single crystal substrate prepared by forming an oxide buffer layer on the resulting oxide template to form an oxide thin film; and subjecting the resulting oxide thin film to an oxygen heat-treatment to complete a thin film superconductor having superconducting properties. That is, the present invention provides a method for fabrication of a thin film superconductor made of REBa2Cu3O7-x (RE = a rare-earth element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and any combination thereof), using a precursor solution prepared by dissolving an inexpensive inorganometallic compound in distilled water. Therefore, the present invention enables production of superconductors at a significantly lower cost, as compared to the use of a conventional expensive β-chelate compound, i.e., 2,2,6,6-tetramethyl-3,5-heptanedione (tmhd).