Intermetallic compounds containing transition metal layers and chains in the Ae-T-X systems (Ae = alkaline-earth metal; T = Fe, Co, Ni; X = III-V main group element) as candidate materials for new superconductors

Discovery of high-temperature superconductivity in iron pnictides/chalcogenides encouraged us to extend our studies to other systems containing transition metals. The search for new compounds with ThCr2Si2-type structure and the alteration of the known 122 phases containing d-metal layers via chemical substitution will be done within this project. Beside the square-planar d-metal layers, which are present in iron-pnictides/chalcogenides, also other planar lattice arrangement or one-dimensional chains of transition metal atoms should be more widely studied with respect to superconducting properties. The syntheses and detailed structural investigations of polar intermetallic compounds in ternary systems Ae-T-X (Ae = alkaline-earth metal, T = Fe, Co, Ni, X = Al, Si, Ge, Sb) could lead to the discovery of new superconducting classes. Preparation of the samples will be done by different high-temperature techniques (arc-melting, induction melting, sintering). The synthesis of high-purity samples and high-quality single crystals for further studies of magnetic and transport properties is one of the goal of our research. X-ray powder and single crystal diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) and thermal analysis will be routinely used for the sample characterization. These investigations will be supplemented by basic electronic structure calculations.

DFG Programme Research Grants