paper

Structural phase transitions and superconductivity in the Heusler intermetallics $X$ Pd $_{2}$ Sn ( $X$ = Ti, Zr, Hf)

arXiv:2303.02908 · doi:10.1103/PhysRevB.106.134517

Abstract

We report the discovery of structural phase transitions and superconductivity in the full Heusler compounds $X$ Pd $_{2}$ Sn ( $X$ = Ti, Zr, Hf), by means of electrical transport, magnetic susceptibility, specific heat and x-ray diffraction measurements. TiPd $_{2}$ Sn, ZrPd $_{2}$ Sn and HfPd $_{2}$ Sn undergo structural phase transitions from the room-temperature cubic MnCu $_{2}$ Al-type structure (space group $F m 3 ˉ m$ ) to a low-temperature tetragonal structure at around 160 K, 110 K and 90 K, respectively, which are likely related charge density wave (CDW) instabilities. Low temperature single crystal x-ray diffraction measurements of ZrPd $_{2}$ Sn demonstrate the emergence of a superstructure with multiple commensurate modulations below $T_{s}$ . ZrPd $_{2}$ Sn and HfPd $_{2}$ Sn have bulk superconductivity (SC) with transition temperatures $T_{c}$ $\sim$ 1.2 K and 1.3 K, respectively. Density functional theory (DFT) calculations reveal evidence for structural and electronic instabilities which can give rise to CDW formation, suggesting that these $X$ Pd $_{2}$ Sn systems are good candidates for examining the interplay between CDW and SC.

10 pages, 8 figures

Structural phase transitions and superconductivity in the Heusler intermetallics XPd2​Sn (X = Ti, Zr, Hf)

Abstract

Structural phase transitions and superconductivity in the Heusler intermetallics $X$ Pd $_{2}$ Sn ( $X$ = Ti, Zr, Hf)