Thermogravimetric and Microgravimetric Studies of the Surface Properties of a High-temperature Superconductor

Abstract

This paper presents possible applications of thermal analysis, sorptomatic and microgravimetric methods for the study of surface adsorption and porosity properties via the programmed thermodesorption of liquid from the sample. The thermodesorption of liquids under quasi-isothermal conditions demonstrates that the adsorption layers on a high superconductor surface possess non-continuous properties. The degradation of the superconducting properties of an YBa₂Cu₃O_7–δsuperconductor sintered in a CO₂-containing atmosphere has been revealed. It is known that atmospheric contaminants such as CO₂ and H₂O can strongly influence the transition temperature, the critical current density, and the width of the superconducting transition of the YBCO superconductor. Similarly to other liquids adsorbed on solid samples, water induces changes in the physicochemical properties at the interface. A good correlation was obtained between the adsorption and porosimetric, thermal analysis and sorptometric findings. The results prove the applicability of these findings for determination of the adsorption capacity.