Phonon profiles in superconducting YNi{sub 2}B{sub 2}C and LuNi{sub 2}B{sub 2}C

Journal Article · Mon Nov 01 04:00:00 EST 1999 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.60.11932· OSTI ID:688034

Zarestky, J; Stassis, C; Goldman, A; Canfield, P ^[1]; Shirane, G; Shapiro, S ^[2]

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1. Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)
2. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

We performed a systematic inelastic neutron scattering, between 4 and 620 K, of the profiles of the anomalous acoustic and optic phonon observed in both compounds in the vicinity of {rvec {xi}}{sub m}{congruent}(0.5 0 0). Above T{sub c} we find that, in both compounds, the frequencies of the acoustic modes decrease with decreasing temperature and there is intensity transfer from the upper (optic) to the lower (acoustic) mode. The frequencies of the optic modes of the Y compound, on the other hand, decrease slower than those of the Lu compound as the temperature decreases towards T{sub c} and, as a result, the two branches approach each other in the Lu compound, whereas they separate in the Y compound. In both compounds the observed phonon profiles above T{sub c} can be described satisfactorily in terms of a simple couple-mode model. Comparison of the phonon spectra of the two compounds below T{sub c} demonstrates that the sharp peak at approximately 4 meV with a broad shoulder at the higher-energy side, observed in both compounds, arises from the change in the acoustic phonon profile upon entering the superconducting state. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 688034
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 60; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON ALLOYS
BORON CARBIDES
CRITICAL TEMPERATURE
INELASTIC SCATTERING
LUTETIUM ALLOYS
LUTETIUM CARBIDES
NEUTRON DIFFRACTION
NICKEL ALLOYS
NICKEL BORIDES
NICKEL CARBIDES
PHONONS
TRANSITION TEMPERATURE