TaRhB and NbRhB: Superconductors with a chiral noncentrosymmetric crystal structure.

It is a fundamental truth in solid compounds that the physical properties follow the symmetry of the crystal structure. Nowhere is the effect of symmetry more pronounced than in the electronic and magnetic properties of materials-even the projection of the bulk crystal symmetry onto different crystal faces is known to have a substantial impact on the surface electronic states. The effect of bulk crystal symmetry on the properties of superconductors is widely appreciated, although its study presents substantial challenges.

New σ-phases in the Nb-X-Ga and Nb-X-Al systems (X = Ru, Rh, Pd, Ir, Pt, and Au).

Previously unreported σ-phases in the ternary niobium-based systems Nb-X-Ga for X = Ru, Rh, Pd, Ir, Pt, Au, and Nb-X-Al for X = Ir, and Pt are presented, prepared by arc-melting followed by annealing at 1000 °C for 1 week. The phases are primitive tetragonal (P4/mnm, no. 136) with lattice parameters of a = 9.