Abstract
is a high-temperature shape-memory alloy with a martensitic transformation temperature strongly dependent on the Cr composition. Prior to the transformation, a premartensitic phase is present with an incommensurate modulated cubic lattice with wave vector of . The temperature dependence of the diffuse scattering in the cubic phase is measured as a function temperature for , 8.5, and . The lattice dynamics has been studied and reveals anomalous temperature and dependences of the transverse phonon branch. The phonon linewidth is broad over the entire Brillouin zone and increases with decreasing temperature, contrary to the behavior expected for anharmonicity. No anomaly is observed at . The results are compared with first principles calculation of the phonon structure.
4 More- Received 10 May 2007
DOI:https://doi.org/10.1103/PhysRevB.76.054305
©2007 American Physical Society