Inelastic neutron studies of the low energy phonon excitations in the RENi{sub 2}B{sub 2}C superconductors (RE=Lu,Y,Ho,Er)

Conference · Fri Aug 01 04:00:00 EDT 1997

OSTI ID:628532

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

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1. Iowa State Univ., Ames, IA (United States). Ames Lab. and Dept. of Physics
2. Brookhaven National Lab., Upton, NY (United States)

We studied the low-energy phonon excitations for wavevectors close to the Fermi surface nesting vector {xi}{sub m} = 0.55 a vector. We find that above T{sub c} the frequencies of the {Delta}{sub 4} [{zeta}00] lowest-lying optical and acoustic phonon modes decrease with decreasing temperature, for {xi} close to {xi}{sub m}, and there is a shift of intensity from the upper to the lower mode, an effect characteristic of coupled modes. From approximately 120K down to temperatures in the vicinity of T{sub c}, only a single unresolved peak is observed. Below Tc the phonon spectra of the Y and Lu compounds change dramatically: it consists of a sharp peak at approximately 4.5 meV with a weak shoulder at the higher energy side. No such sharp peak was observed below T{sub c} in the Ho and Er compounds.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 628532
• Report Number(s): BNL--64633; CONF-970814--; ON: DE97008943
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BORON COMPOUNDS
CARBON COMPOUNDS
EXCITATION
FERMI LEVEL
NICKEL COMPOUNDS
PHONONS
RARE EARTH COMPOUNDS
SUPERCONDUCTORS
TRANSITION TEMPERATURE