Oxygen Tracer Diffusion in La2-xSrxCuO4-y Single Crystals

• Published in: Journal of the American Ceramic Society 1993-09, Vol.76 (9), p.2363-2369
• Main Authors: Opila, Elizabeth J., Tuller, Harry L., Wuensch, Bernhardt J., Maier, Joachim
• Format: Article
• Language: English
• Subjects: Chemical interdiffusion; diffusion barriers; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cuprates superconductors (high tc and insulating parent compounds); Diffusion in solids; Exact sciences and technology; High-Tc compounds; La-based cuprates; Physics; Properties of type I and type II superconductors; Superconductivity; Transport properties (electric and thermal conductivity, thermoelectric effects, etc.); Transport properties of condensed matter (nonelectronic)
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1151-2916.1993.tb07778.x

The tracer diffusion of 18O in La2‐xSrxCuO4‐y single crystals (x = 0 to 0.12) has been measured from 400° to 700°C in 1 atm of oxygen using SIMS analysis. Evidence for diffusion by a vacancy mechanism was found at low strontium contents. Oxygen diffusivities for x 2≥ 0.07 were depressed by several orders of magnitude below the diffusivity for undoped La2CuO4±y. The observed effects of strontium doping on oxygen diffusivity are discussed in terms of defect chemical models. The decreasing oxygen diffusivity with increasing strontium was attributed to the ordering of oxygen vacancies at large defect concentrations. A diffusion anisotropy, Dab/Dc, of ∼600) was also found at 500°C.