Structural phase transitions and superconductivity in the Heusler intermetallics XPd2Sn (X = Ti, Zr, Hf)

Article

关键词: CHARGE-DENSITY-WAVE;    QUANTUM CRITICAL-POINT;    ENTHALPIES;    DYNAMICS;   

DOI  :  10.1103/PhysRevB.106.134517

来源: SCIE

【 摘 要 】

We report the discovery of structural phase transitions and superconductivity in the full Heusler compounds XPd2Sn (X = Ti, Zr, Hf), by means of electrical transport, magnetic susceptibility, specific heat, and x-ray diffraction measurements. TiPd2Sn, ZrPd2Sn, and HfPd2Sn undergo structural phase transitions from the room-temperature cubic MnCu2Al-type structure (space group Fm3 over bar m) to a low-temperature tetragonal structure at around 160, 110, and 90 K, respectively, which are likely related to charge density wave (CDW) instabilities. Low-temperature single-crystal x-ray diffraction measurements of ZrPd2Sn demonstrate the emergence of a superstructure with multiple commensurate modulations below Ts. ZrPd2Sn and HfPd2Sn have bulk supercon-ductivity with transition temperatures Tc similar to 1.2 and 1.3 K, respectively. Density functional theory calculations reveal evidence for structural and electronic instabilities which can give rise to CDW formation, suggesting that these XPd2Sn systems are good candidates for examining the interplay between CDW and superconductivity.

【 授权许可】

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