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Oxygen Tracer Diffusion in La 2‐x Sr x CuO 4‐y Single Crystals
Author(s) -
Opila Elizabeth J.,
Tuller Harry L.,
Wuensch Bernhardt J.,
Maier Joachim
Publication year - 1993
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1993.tb07778.x
Subject(s) - thermal diffusivity , oxygen , strontium , diffusion , tracer , analytical chemistry (journal) , chemistry , anisotropy , vacancy defect , self diffusion , doping , materials science , mineralogy , crystallography , thermodynamics , physics , self service , optoelectronics , organic chemistry , chromatography , quantum mechanics , marketing , nuclear physics , business
The tracer diffusion of 18 O in La 2‐x Sr x CuO 4‐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 La 2 CuO 4±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, D ab / D c , of ∼600) was also found at 500°C.