DETERMINATION OF THERMALLY LABILE OXYGEN IN HIGH TEMPERATURE SUPERCONDUCTING CERAMICS BY METASTABLE TRANSFER EMISSION SPECTROSCOPY.

A microwave induced discharge spectroscopic analyzer is described for determining oxygen and carbon evolution versus temperature profiles of solids. Profiles of oxygen and carbon evolved from Ba sub 2 YCu sub 3 O sub 7 over the temperature range 50 to 1000C are obtained by chemiluminescent formation of NO and CN resulting from reactions with active nitrogen. Intensity profiles measured at 304.3 and 388.3 nm respectively show coincident maxima at 750 and 930C for O sub 2 and CO sub x evolution. In the case of O sub 2 evolution is observed also over the broad range 175degrees to 975degrees with an additional maximum at approximately 490C. Integration of NO intensity over time compared to results from calibration curves using known gases provided a means of determining the mass of oxygen evolved from samples. Comparisons showed the metastable transfer emission spectroscopic results to be within +- 10% of the gravimetric result with a correlation coefficient of > 0.95.