Material synthesis of HgBa2Can-1CunOy multilayered cuprates under high pressure

Abstract

Multilayered cuprates having crystallographically inequivalent CuO2 planes are worthful materials to realize the mechanism of high-Tc superconductivity as well as a stage to ascertain new phenomena. The material synthesis of HgBa2Can-1CunOy multilayered cuprates by employing high-pressure synthesis technique is demonstrated. A starting mixture with a composition ratio of Hg:Ba:Ca:Cu:O = 1:2:n-1:n:2n+2+δ was synthesized by mixing the precursor of Ba2Ca2Cu3Oy (y~7.5) with an appropriate amount of HgO, Ca2CuO3, CuO and Cu2O (or Cu). The oxygen content of the mixture was adjusted incisively by ascertaining a ratio of CuO, Cu2O (or Cu) to obtain samples. Almost single-phase samples up to n = 6 were synthesized. The X-ray diffraction analysis of the grain-aligned sample with nominal compositions of n ⩾ 7 revealed that the sample simultaneously comprises from n = 6 up to 16 phases.