Calculated sound velocity and elastic moduli changes of FeTe0.5Se0.5 at the superconducting transition. (June 2017)

• Record Type: Journal Article
• Authors: Abd-Shukor, R.; Chen, S.K.; Lim, Edmund H.H.
• Is Part Of: Solid state communications. Volume 259(2017)
• Page Start: 7
• Page End: 9
• Publication Date: 2017-06
• Subjects: Electron-phonon coupling -- Elastic properties -- FeTe0.5Se0.5 -- Superconductors -- Young modulus; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2017.04.020
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: The room temperature sound velocity in FeTe0.5 Se0.5 superconductor has been measured using the pulsed-echo overlap ultrasonic technique. The samples were prepared using the solid-state reaction method at ambient pressure. Using these ultrasonic measurements we performed calculations that showed a step discontinuity in the bulk modulus, ∆ B B =4 ppm, Young's modulus, ∆ Y Y =8 ppm and longitudinal sound velocity, ∆ v L v L =2 ppm at T c . The calculated acoustic Debye temperature, θ D =334 K indicated that FeTe0.5 Se0.5 is slightly softer than the copper oxide based superconductor and hence the lower T c . The calculated electron-phonon coupling in the two-dimensional van Hove scenario is, λ vH =0.024. Highlights: The room temperature sound velocities in FeTe0.5 Se0.5 have been measured using ultrasonic technique. The acoustic Debye temperature of FeTe0.5 Se0.5 was determined to be 334 K. An upper limit for a possible BCS-type lattice softening at T c based on the elastic moduli is given.