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2. ? values of 0.077, 0.063, and 0.052 were obtained by annealing for 12h at temperatures of 400, 450, and 500°C, respectively, in 2% O2/N2.? =0.032 was obtained by annealing for 10 h at 525°C in 80 ppm O2/Ar, and? values of 0.017 and 0.001 were obtained by annealing for 8 h at temperatures of 560 and 600°C, respectively, in 80 ppm O2/Ar.
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