Anomalous phonon behavior in the high-temperature shape-memory alloy Ti{sub 50}Pd{sub 50-x}Cr{sub x}

Journal Article · Wed Aug 01 04:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.76.054305· OSTI ID:21055102

Shapiro, S M; Guangyong, Xu; Winn, B L; Schlagel, D L; Lograsso, T; Erwin, R ^[1]

---

1. 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, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 5 Vol. 76; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BRILLOUIN ZONES
CHROMIUM ALLOYS
CUBIC LATTICES
DIFFUSE SCATTERING
PALLADIUM ALLOYS
PHASE TRANSFORMATIONS
PHONONS
SHAPE MEMORY EFFECT
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
TITANIUM ALLOYS
VECTORS