Anomalous phonon behavior in the high-temperature shape-memory alloy Ti{sub 50}Pd{sub 50-x}Cr{sub x}
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)
Ti{sub 50}Pd{sub 50-x}Cr{sub x} 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 q{sub 0}=(0.22,0.22,0). The temperature dependence of the diffuse scattering in the cubic phase is measured as a function temperature for x=6.5, 8.5, and 10 at. %. The lattice dynamics has been studied and reveals anomalous temperature and q dependences of the [110]-TA{sub 2} 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 q{sub 0}. The results are compared with first principles calculation of the phonon structure.
- OSTI ID:
- 21055102
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 76, Issue 5; Other Information: DOI: 10.1103/PhysRevB.76.054305; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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