Chemical diffusion of oxygen in single-crystal and polycrystalline YBa2Cu3O6+x determined by electrical-resistance measurements.

Abstract

Isothermal electrical-resistance measurements were used to monitor oxygen diffusion kinetics in both single-crystal and polycrystalline YBa 2 Cu 3 O 6+x between 350 and 780 o C. Distinctions are made between intrinsic diffusion behavior and microstructure-dependent properties. An activation energy of 0.4(1) eV was determined for oxygen in-diffusion in dense polycrystalline material from 400 to 780 o C, and 1.10(6) eV for single crystals between 600 and 780 o C. Below 600 o C, the activation energies for out-diffusion in porous and dense polycrystalline specimens were determined to be 0.5(1) eV and 0.6(1) eV, respectively