Iridium 5d-electron driven superconductivity in ThIr3

Karolina Górnicka; Debarchan Das; Sylwia Gutowska; Bartłomiej Wiendlocha; Michał J. Winiarski; Tomasz Klimczuk; Dariusz Kaczorowski

doi:10.1103/PhysRevB.100.214514

Iridium 5d-electron driven superconductivity in ThIr3

Karolina Górnicka, Debarchan Das, Sylwia Gutowska, Bartłomiej Wiendlocha, Michał J. Winiarski, Tomasz Klimczuk, Dariusz Kaczorowski

DOI 10.1103/PhysRevB.100.214514 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

A polycrystalline sample of superconducting ThIr3 was obtained by arc-melting Th and Ir metals. Powder x-ray diffraction revealed that the compound crystalizes in a rhombohedral crystal structure (R-3m, s.g. #166) with the lattice parameters: a=5.3394(1)Å and c=26.4228(8)Å. Normal and superconducting states were studied by magnetic susceptibility, electrical resistivity, and heat capacity measurements. The results showed that ThIr3 is a type-II superconductor (Ginzburg-Landau parameter κ=38) with the critical temperature Tc=4.41K. The heat capacity data yielded the Sommerfeld coefficient γ=17.6mJ/(molK2) and the Debye temperature ΘD=169K. The ratio ΔC/(γTc)=1.6, where ΔC stands for the specific heat jump at Tc, and the electron–phonon coupling constant λe−p=0.74 suggest that ThIr3 is a moderate-strength superconductor. The experimental studies were supplemented by band structure calculations, which indicated that the superconductivity in ThIr3 is governed mainly by 5d states of iridium. The significantly smaller band-structure value of Sommerfeld coefficient as well as the experimentally observed quadratic temperature dependence of resistivity and enhanced magnetic susceptibility suggest the presence of electronic interactions in the system, which compete with superconductivity.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
ThIr3 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	4.41	Pressure not reported	unknown
ThIr3 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	4.4	Pressure not reported	onset
LaIr3 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	3.5	Pressure not reported	unknown
CeIr3 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	2.5	Pressure not reported	unknown