Evidence for multiple superconducting gaps in the filled skutterudite compound LaRu4As12

Electron-phonon superconductivity in the filled skutterudites LaRu4P12, LaRu4As12 , and Tütüncü1, Karaca2, Srivastava3 2017Phys. Rev. B

“…However, our calculated elastic constants for LaRu 4 As 12 agree very well with previous GGA calculations [65]. Furthermore, the calculated Debye temperatures of all studied materials are comparable with their corresponding experimental results [38,44,46,49]. These two results indicate that our elastic results for all the considered materials should show good agreement with any future measurements.…”

“…Also, lanthanum compounds display interesting superconducting behavior at low temperatures [37][38][39][40][41][42][43][44][45][46][47]. The superconducting transition temperature (T c ) of LaRu 4 X 12 with X = P, As, Sb is found to be 7.2, 10.3, and 2.8 K [37,38,42,43].…”

“…Recently, superconducting properties of the filled skutterudite compound LaRu 4 As 12 have been investigated as a function of both temperature and magnetic field in the experimental work of Bochenek and co-workers [46]. These authors took advantage of its high critical temperature (T c ) and high critical field (H c2 ∼ 10.2 T) to make investigations in a wide range of temperatures and magnetic fields.…”

Superconducting gap structure of the skutteruditeLaPt4Ge12probed by specific heat and thermal transport

“…This value is in resonable agreement with the results from photoelectron spectroscopy: ∆ 0 = 1.95 k B T c 16 , and NMR: ∆ 0 = 1.92 k B T c 12 . Since superconductivity in other skutterudites is discussed in terms of multiband superconductivity 13,[24][25][26] and there are results in favor of this interpretation for LaPt 4 Ge 12 as well 21 , we also consider this possibility based on our specific-heat data. In the case of two gaps, the specific heat might be described by a weighted sum of the contributions from both gaps within the standard two-gap α-model…”

Specific Heatof the Filled Skutterudite Superconductor LaOs4As12

“…Remarkable that LaRu 4 As 12 , adopting the same filled skutterudite crystal structure, displays several features indicative of two-band superconductivity, although a lack of 4f electrons makes its electronic structure less complex. A compelling evidence for more than one energy gap in LaRu 4 As 12 holds for (i) a nonlinear magnetic field B dependence of the specific heat in the zero-temperature limit, (ii) a positive curvature of the B c2 (T ) dependence, and (iii) a deviation of the electronic specific heat from the one-gap α model [14]. Physical properties of LaOs 4 As 12 have been investigated by different groups.…”