Exploration of Novel Intermetallic Superconductors

Abstract

I report the discovery of the new superconductor TaIr\(_{2}\)Ge\(_{2}\), which has a critical temperature around 3.5 K. This material crystallizes in an entirely new orthorhombic structure type consisting of endohedral Ta@Ir\(_{7}\)Ge\(_{4}\) clusters, one that is more complex than those of the more commonly observed 1:2:2 intermetallic phases. The superconducting transition of this compound is characterized by temperature-dependent resistivity, magnetic susceptibility, and specific heat measurements, and is of the weak coupling BCS type with \(\Delta \text{C/}\gamma \text{T}_c\) =1.55. In addition, I explore known structure types with the goal of generating new superconducting compounds, either by elemental substitution or by the addition of a small element to an already existing structure. This search led to the synthesis of three previously unreported phases: LuPd\(_3\)Si\(_x\), TmB\(_3\)B\(_{1-x}\)Si\(_x\), and Zr\(_4\)Mn\(_4\)Si\(_7\). Further work on these systems may lead to the identification of other new superconducting materials.