Observation of high-Tc superconductivity in inhomogeneous combinatorial ceramics

Mitra Iranmanesh; Nikolai D. Zhigadlo; Thanaporn Tohsophon; John R. Kirtley; Wilfried Assenmacher; Werner Mader; Jürg Hulliger

doi:10.1016/j.solidstatesciences.2018.12.003

arXiv · 1812.06273

Observation of high-Tc superconductivity in inhomogeneous combinatorial ceramics

Mitra Iranmanesh·Nikolai D. Zhigadlo·Thanaporn Tohsophon·John R. Kirtley·Wilfried Assenmacher·Werner Mader·Jürg Hulliger

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Abstract

A single-sample synthesis concept based on multi-element ceramic samples can produce a variety of local products. When applied to cuprate superconductors (SC), statistical modelling predicts the occurrence of possible compounds in a concentration range of about 50 ppm. In samples with such low concentrations, determining which compositions are superconducting is a challenging task and requires local probes or separation techniques. Here, we report results from samples with seven components: BaO2, CaCO3, SrCO3, La2O3, PbCO3, ZrO2 and CuO oxides and carbonates, starting from different grain sizes. The reacted ceramics show different phases, particular grain growth, as well as variations in homogeneity and superconducting properties. High-Tc superconductivity up to 118 K was found. Powder x-ray diffraction (XRD) in combination with energy-dispersive spectroscopy (EDS), scanning transmission electron microscopy (STEM) can assign Pb1223 and (Sr,Ca,Ba)0.7-1.0CuO2 phases in inhomogeneous samples milled with 10 mm ball sizes. Rather uniform samples featuring strong grain growth were obtained with 3 mm ball sizes, resulting in Tc =70 K superconductivity of the La(Ba,Ca)2Cu3Ox based phase. Scanning SQUID microscopy (SSM) establishes locally formed superconducting areas at a level of a few microns in inhomogeneous superconducting particles captured by a magnetic separation technique. The present results demonstrate a new synthetic approach for attaining high-Tc superconductivity in compounds without Bi, Tl, Hg, or the need for high-pressure synthesis.

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Mitra Iranmanesh, Nikolai D. Zhigadlo, Thanaporn Tohsophon, John R. Kirtley, Wilfried Assenmacher, Werner Mader, Jürg Hulliger. 2018-12-15. Observation of high-Tc superconductivity in inhomogeneous combinatorial ceramics. https://doi.org/10.1016/j.solidstatesciences.2018.12.003

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