Calculated elastic moduli and sound velocity changes in YH6 hydride superconductor at the transition temperature

• Main Authors: K.V. Lee, R. Abd-Shukor
• Format: Article
• Language: English
• Published: Elsevier 2020-12-01
• Series: Results in Physics
• Subjects: Bulk modulus; Sound velocity; Young modulus; Ultrasonic; van Hove
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211379720321069

Yttrium hexahydride, YH6 with transition temperature, Tc of 224 K in high pressure of 165 GPa is interesting because it has the highest pressure application efficiency. In this paper, we calculated the discontinuity in the elastic moduli and longitudinal sound velocity at Tc of YH6. The calculated changes at Tc in the bulk modulus, ΔBB is 43 ppm, Young’s modulus, ΔYY is 46 ppm and longitudinal sound velocity, ΔvLvL is 15 ppm. These results showed the role of phonons in this hydride superconductor and the values are within the range of most ultrasonic techniques. The van Hove scenario may be relevant in YH6 due to the large density of states near the Fermi level. In this paper the electron-phonon coupling constant of YH6 in this scenario was calculated to be λvH = 0.040. The elastic anomalies at the transition temperature were compared with other type of superconducting materials.