Abstract Body

Layered compounds, such as cuprates, iron-pnictides, and HfNCl, are a showcase of superconductors with high T_c. Among them, ZrP_2-xSe_x is a layered superconductor [1] and is thought to have the potential to exhibit a higher T_c by modifying electron filling, band width and so on.  ZrCuP₂, which has a structure in which a nonmagnetic Cu layer is inserted into ZrPSe, is a promising candidate for a new superconductor [2]. The crystal structure of ZrCuP₂ is identical to that of the existing material ZrCuSiP [3], and is also identical to that of LaOFeAs, which has the highest T_c among iron-pnictide superconductors.

In this study, we performed first-principles electronic structure calculations for ZrCuP₂ and its related compound ZrNiP₂. In ZrNiP₂, a large increase in the density of states just below the Fermi level is observed, which is generally favorable for high-T_c superconductivity [4]. We also calculated the phonon dispersion and the electron-phonon interaction for these compounds and estimated their T_c using the isotropic approximation.

References

[1] H. Kito et al.  J. Phys. Soc. Jpn. 83, 074713 (2014)
[2] I. Hase et al.  PCP-4, 36^th International Symposium on Superconductivity (ISS2023), 29 Nov. (2023), Wellington
[3] H. Abe and K. Yoshii,  J. Solid State Chem. 165, 372 (2002).
[4] V. Stanev et al.  npj Comput. Mater. 4, 29 (2018)

Figure 1. Density of States of ZrNiP₂ and ZrCuP₂.

Keywords: Superconductivity, First-principles calculation, Layered structure, ZrCuP₂, ZrNiP₂