Adsorption of oxygen on YBa2Cu3O7-x and (Bi,Pb)(2)Sr2Ca2Cu3Ox superconducting adsorbents

The adsorption of oxygen on a high-temperature superconductor is not inhibi ted by superconducting forces. The equilibrium adsorption isotherms of oxyg en and nitrogen on superconducting YBa2Cu3O7-x and (Bi,Pb)(2)Sr2Ca2Cu3Ox at 17 K are equivalent. Moreover, the equilibrium adsorption of oxygen on sup erconducting YBa2Cu3O7-x and (Bi,Pb)(2)Sr2Ca2Cu3Ox and on nonsuperconductin g SiO2 at 77 K are equivalent. These results agree with theoretical argumen ts that predict the magnetic repulsion of oxygen from a superconductor to b e significant over a distance of angstroms. At these distances, the magneti c forces are constrained by the superconductor's penetration depth and no M eissner effect is observed, contrary to the results of past reports.