Synthesis of non-toxic analogs of (Tl/Hg)BaCaCuO superconductors

The (Tl/Hg)BaCaCuO family of superconductors exhibits the highest critical temperatures at atmospheric pressure (approximately 140 K), discovered in the 90s, but development and applications of these compounds have been limited by their toxicity. In this study, Indium and Tin were substituted for Mercury and Thallium, which may lead to the discovery of novel non-toxic superconducting compounds with a high T_c. These compounds were synthesized using a solid-state reaction technique that involved grinding the required powders until homogeneous, pressing the mixture into pellets, and annealing at 950°C in a controlled oxygen flow. The chemical composition was varied systematically. The lattice structure of these compounds was analyzed using X-ray diffraction, and the results were compared with the structure and phases of the TlHg compounds. Electronic transport and magnetic measurements were performed using a Physical Properties Measurement System. Results of the XRD, transport, and magnetic measurements will be discussed.