Rattling enhanced superconductivity in MV${}_2$Al${}_{20}$ (M = Sc, Lu, Y) intermetallic cage compounds

Abstract

Polycrystalline samples of four intermetallic compounds: MV${}_2$Al${}_{20}$ (M = Sc, Y, La, and Lu) were synthesized using an arc-melting technique. The crystal structures were analyzed by means of powder x-ray diffraction and Rietveld analysis, and the physical properties were studied by means of heat capacity, electrical resistivity and magnetic susceptibility measurements down to 0.4 K. For ScV${}_2$Al${}_{20}$, LuV${}_2$Al${}_{20}$, and YV${}_2$Al${}_{20}$, superconductivity was observed with critical temperatures T${}_c$ = 1.00 K, 0.57 K, and 0.60 K, respectively. Superconductivity for the Lu compound is reported for the first time. Theoretical calculations of the electronic and phonon structures were conducted in order to analyze the superconductivity and dynamics in ScV${}_2$Al${}_{20}$, YV${}_2$Al${}_{20}$, and LuV${}_2$Al${}_{20}$ and to explain the lack of a superconducting transition in LaV${}_2$Al${}_{20}$ down to 0.4 K. The results of the experimental and theoretical studies show that all the compounds are weakly-coupled type II BCS superconductors, and reveal the importance of the M-atom anharmonic "rattling" modes for the superconductivity in these materials, which seem to enhance T${}_c$, especially for ScV${}_2$Al${}_{20}$.

34 pages (+ supplemental material), 15 figures (+ 4 in suppl. mat.); Accepted for publication in Physical Review B

References in corpus (12)

• Heavy Fermion Superconductivity in the Quadrupole Ordered State of PrV2Al20
• Superconductivity in the Heusler Family of Intermetallics
• Extremely strong-coupling superconductivity and anomalous lattice properties in the beta-pyrochlore oxide KOs2O6
• Rattling-Induced Superconductiviy in the Beta-Pyrochlore Oxides AOs2O6
• On the importance of the electron-phonon coupling function on the superconducting transition temperature in dodecaboride superconductors: A comparison of LuB12 with ZrB12
• Phonon density of states, anharmonicity, electron-phonon coupling and possible multigap superconductivity in the clathrate superconductors Ba8Si46 and Ba24Si100: Why is Tc different in these two compounds?
• Theoretical search for superconductivity in Sc3XB perovskites and weak ferromagnetism in Sc3X (X = Tl, In, Ga, Al)
• Low-Energy Optical Phonon Modes in the Caged Compound LaRu2Zn20
• Pressure effects on the superconductivity of HfPd2Al Heusler compound: Experimental and theoretical study
• Unusual signatures of the ferromagnetic transition in the heavy Fermion compound UMn${}_2$Al${}_{20}$
• A Possible Phase Transition in beta-pyrochlore Compounds
• Large Diamagnetism of AV2Al20 (A = Y and La)

Cited by in corpus (6)

• Crystal structure and low-energy Einstein mode in ErV${}_2$Al${}_{20}$ intermetallic cage compound
• Synthesis and properties of A${}_x$V${}_2$Al${}_{20}$ (A = Th, U, Np, Pu) ternary actinide aluminides
• Superconductivity in Cage Compounds La$T{r}_2$Al${}_{20}$ with $Tr$ = Ti, V, Nb, and Ta
• Ab initio study on magnetism suppression, anharmonicity, rattling mode and superconductivity in Sc${}_{6}M$Te${}_2$ ($M$=Fe, Co, Ni)
• Structural Trends and Itinerant Magnetism of the New Cage-structured Compound HfMn${}_2$Zn${}_{20}$
• Superconductivity in the layered cage compound Ba3Rh4Ge16