Incommensurate strain-induced ordering of interstitial oxygen in Nb.

ABSTRACT

We present a semi-phenomenological theory of the strain-induced interaction between interstitial oxygen dissolved in Nb and predict an incommensurate oxygen ordering wave which is mediated by the intrinsic bcc instability at k = 2/3(111). We discuss the stability range of this ordering phenomenon, which may play a role in the performance of Nb radio frequency (RF) cavities for high energy particle accelerators.