Oxygen In Tantalum Research Articles

Internal friction in solid solutions of oxygen-tantalum

The breadth of the internal friction peak (Q − vs 1 T ) arising from the diffusion of oxygen in tantalum has been found to increase monotonically with the oxygen concentration. Broadening was found to occur asymmetrically by displacement of the high-temperature branch of the damping curve. The data can be described by assuming that the experimental internal friction peak is a composite of the dilute oxygen peak found at 137°C (for v = 0.6 cps), with an activation energy of 25,000 cal/mole, and a second peak located near 162°C. Evidence is presented which indicates that the peak previously attributed to carbon in tantalum actually is caused by oxygen at low concentrations. In an attempt to determine the nature of the interaction giving rise to the broadening of the oxygen peak, it was observed that atoms of another element, nitrogen, can also broaden it considerably. Plastic deformation apparently did not affect the peak breadth.