Calcium-free double-layered cuprate superconductors with critical temperature above 100 K

Abstract Calcium is a vital constituent in multilayered cuprate superconductors with critical temperatures ( T c ) above 100 K, because it plays key role separating CuO 2 planes. Here, we demonstrate the synthesis of calcium-free double-layered cuprates: Sr SrCu O 4 X ,O) = F, Cl, and Br) M (Sr,Ba) y Hg/Re, Tl, B/C), where strontium exists between Oxyfluoride mercury-based materials show 107 K 110 respectively, which are high compared to existing cuprates. These findings indicate greater than can be realized by replacing both barium calcium, have been indispensable conventional cuprates, strontium. Furthermore, non-toxicity F (B,C)Sr simplifies process ensures their safety potential applications. We also perform comparison characteristic structural parameters calcium-containing cuprates considering number