The existence of a new metallic carbide of composition Th 3Ni5C5 was reported in the literature in 1991. This compound is a new orthorhombic prototype structure. In this work we report a reinvestigation of the synthesis of this material and we find that the Th 3Ni5C5 compound is a new bulk superconducting material. Despite the high concentration of Ni in this compound, we find bulk superconductivity with superconducting critical temperature of Tc = 5.0K and an upper critical field of μoHc2 = 5.8T. Details of the superconducting state with specific heat, magnetization, and resistivity measurements are discussed. © 2011 IOP Publishing Ltd.

The metallic carbides exhibit many novel prototypes of crystalline structure. Among these compounds Th 2NiC 2 was reported in 1991 as a new carbide which crystallizes in the U 2IrC 2 prototype structure. In this work we report a reinvestigation of the synthesis of this compound. We find that Th 2NiC 2 is a new superconductor. Our results suggest that this phase is stable only at high temperatures in the system ThNiC. The substitution of Th by Sc stabilizes the phase and improves the superconducting properties. The highest superconducting critical temperature occurs at 11.2K with nominal composition Th 1.8Sc 0.2NiC 2. The electronic coefficient determined by specific heat measurements is close to zero. This unusual result can be explained by covalent bonding in the compound. © 2012 IOP Publishing Ltd.

Superconductivity in compounds whose crystal structure lacks inversion symmetry are known to display intriguing properties that deviate from conventional BCS superconducting behavior. Here we report magnetization, resistivity, and heat capacity measurements on polycrystalline samples of ThCoC2, which has been reported to crystallize in the non-centrosymmetric CeNiC2 prototype structure, and show clear evidence of bulk superconductivity in ThCoC2 with a critical temperature of Tc = 2.65 K. From the specific heat data we find a Sommerfeld coefficient of γ = 8.38 mJ mol-1 K-2 and a Debye temperature of ΘD = 449 K. Interestingly the H c2 superconducting phase diagram displays positive curvature, and the specific heat at low temperature deviates from conventional exponential temperature dependence, which is suggestive of possible unconventional superconducting behavior in ThCoC2, similar to that seen in the isostructural and isoelectronic non-centrosymmetric superconductor LaNiC 2. © 2014 IOP Publishing Ltd.

In this work the Nb2InC phase is investigated by X-ray diffraction, heat capacity, magnetic and resistivity measurements. Polycrystalline samples with Nb2InC nominal compositions were prepared by solid state reaction. X-ray powder patterns suggest that all peaks can be indexed with the hexagonal phase of Cr2AlC prototype. The electrical resistance as a function of temperature for Nb2InC shows superconducting behavior below 7.5 K. The M(H) data show typical type-II superconductivity with HC1 ∼ 90 Oe at 1.8 K. The specific heat data are consistent with bulk superconductivity. The Sommerfeld constant is estimated as γ ∼ 12.6 mJ mol-1 K-1. © 2009 Elsevier B.V. All rights reserved.

In the MoSi binary system, Mo5Si3 crystallizes in the W5Si3 (T1 phase) structure type. However, when boron replaces silicon in this compound, a structural transition occurs from the W5Si3 prototype structure to the Cr5B 3 prototype structure (T2 phase) at the composition Mo5SiB2. Mo5SiB2 has received much attention in the literature as a candidate for structural application in high-temperature turbines, but its electronic and magnetic behavior has not been explored. In this work, we show that Mo5SiB2 is a bulk superconducting material with critical temperature close to 5.8 K. The specific-heat, resistivity and magnetization measurements reveal that this material is a conventional type II BCS superconductor. © 2011 Elsevier Ltd. All rights reserved.

In this work the Ti2InN phase is investigated by X-ray diffraction, magnetic and resistivity measurements. X-ray powder patterns suggest that all peaks can be indexed with the hexagonal phase of Cr 2AlC prototype. Electrical resistance as a function of temperature reveals superconductivity below 7.3 K. M(H) hysteresis loops show typical type-II superconductivity. Using R(H) versus T measurements we estimated μoHc2(0)∼10.8T and ξ(0)∼55.2 Å. The results show unambiguously that Ti2InN is the first nitride superconductor belonging to the Mn+1AXn family. © 2010 Elsevier Ltd. All rights reserved.

© 2015 Elsevier B.V. In this work, we report superconductivity at 5.5 K in the new pseudo-ternary Th0.93Zr0.07B12 compound. We show clearly evidence that appropriate amounts of Zr substitution at the Th site induce the stabilization of the UB12 prototype structure at ambient pressure. The superconducting bulk properties of Th0.93Zr0.07B12 are confirmed by means of magnetization, electronic transport properties and specific heat measurements. The H-T phase diagrams based on magnetization and magnetoresistance measurements yield μ0Hc1(0)=6 mT and μ0Hc2(0)=98 mT and allow us to estimate the coherence length ξo~57.9 nm and the penetration depth λL~234 nm at zero kelvin.

In this work, we report superconductivity at 5.5 K in the new pseudo-ternary Th0.93Zr0.07B12 compound. We show clearly evidence that appropriate amounts of Zr substitution at the Th site induce the stabilization of the UB12 prototype structure at ambient pressure. The superconducting bulk properties of Th0.93Zr0.07B12 are confirmed by means of magnetization, electronic transport properties and specific heat measurements. The H-T phase diagrams based on magnetization and magnetoresistance measurements yield μ0Hc1(0)=6 mT and μ0Hc2(0)=98 mT and allow us to estimate the coherence length ξo∼57.9 nm and the penetration depth λL∼234 nm at zero kelvin.

We report bulk superconductivity in ZrVGe withTc=6K determined by magnetization, electronic transport and specific heat measurements. From the analysis of magnetization and resistivity data we obtain the thermodynamic critical fieldsμ0Hc1andμ0Hc2, respectively. The heat capacity data deviate from conventional BCS theory suggesting possible unconventional superconducting behavior.