Rapid technique for dissolution of nitrides

Abstract

Stripping Efficiency. The water flow rate was varied while holding the stripping gas flow constant at 20 ml/min. The nitrogen peak areas increased linearly with increasing WFR to about 12 ml/min indicating complete stripping. The pumps are normally run at 4 ml/min. Effect of Hydrazine Concentrations. Experiments demonstrated that reducing the hydrazine sulfate concentration by one half had no effect on the yield of NO. The yield was linear over the current densities used.Precision and Accuracy. The relative standard deviation is typically 0.5 for 4 samples. The accuracy is more difficult to assess: The resistor was calibrated to 1000.01 ohms. The digital integrator is accurate to 0.1 (ignoring false base-line tripping due to signal noise). The digital voltmeter is calibrated to 0.2%. The flow measurement is certainly accurate to 0.1 %. Therefore, the total error in accuracy is at most 0.5 %, Seawater Itesults. About 300 samples were successfully analyzed for Nz and Ar in this laboratory and aboard ship during the pa st year. ACKNOWLEDGMENTThe author thanks P. J. Wangersky, R. C. Cooke, and T.Yoshinari for advice in developing this method.

Conversion of [(tBuCH2)2TaN]5 to Cubic TaN: Related Syntheses, EHMO Calculations, and MAS and Spin Echo 15N NMR Spectroscopies

“…The values obtained suggested that the correct formulation for 5 was TaN 0.8 , but the degradation did not occur smoothly. Although boiling H 3 PO 4 /SnCl 2 was found to dissolve 5 , , the resulting mixture was heterogeneous, with gray-black coloration indicative of an incomplete reaction, and thus the nitrogen number is believed to be a lower limit (i.e., TaN ≥ 0.8 ). Alternative methods, including boiling HF, failed to decompose 5 .…”

Nitrogen Diffusion in Zirconium Nitride

“…The composition of the plates was computed from the weight gain during nitridation, the result being checked by chemical analyses. Nitrogen analysis was conducted using Bollman's modified Kjeldahl method in which the dissolving medium is a stannous-phosphoric acid reagent (9). The zirconium content was deduced from the weight of ZrO2 obtained by reacting a ZrN sample in oxygen for 24 hr at 1000~…”