Large anisotropic vibrational correlations in A15 Nb3Ge

Abstract

Extended x-ray-absorption fine-structure measurements on Nb3Ge at temperatures from 8 to 300 K using the Nb K edge show large anisotropies in nearest-neighbor vibrational correlations arising from one-dimensional transition-metal chains in the A15 structure. A simple view of these vibrations involves combinations of optical phonons which cause chains of Nb atoms to vibrate, nearly undistorted within the bcc lattice of Ge atoms, uncorrelated with vibrations of adjacent, perpendicular Nb chains. © 1983 The American Physical Society.