Abstract: A high-temperature superconducting wire material comprising: a pre-superconducting wire material layer formed by forcibly removing a metal substrate from a superconducting wire material formed by including the metal substrate, a buffer layer formed on the upper surface of the metal substrate and a superconducting conductive layer formed on the upper surface of the buffer layer; a silver (Ag) protective layer formed on the lower surface of the pre-superconducting wire material layer; and a copper (Cu) protective layer formed on the lower surface of the Ag protective layer.

Abstract: Disclosed herein is a method of preparing a yttria solution for a buffer layer of a substrate, including the steps of: (a) mixing yttrium acetate tetrahydrate with methanol to form a mixture and then stirring the mixture; (b) injecting diethanolamine as a chelating agent into the mixture of the step (a) and then stirring the mixture to synthesize a composite; and (c) filtering the composite synthesized in the step (b) using a filter to obtain a sol. The method is advantageous in that the yttria solution prepared in this method is applied onto a substrate to flatten the substrate, and is used to form a diffusion barrier serving as a buffer layer for preventing the diffusion of a substrate material.