Superconducting transition temperature in mercury HTSC-cuprates under hydrostatic pressure

Publisher Website
Google Scholar
Abstract
A study is made of the properties of the homologous series of mercury HTSC-cuprates HgBa2Can−1CunO2n+2+δ with n=1–8. Experiments are conducted under pressure for samples with n=1–5. The Hg-1223 and Hg-1234 phases were synthesized using a controlled high pressure chamber. The oxygen content of an initial mixture corresponding to the Hg-1234 phase was varied by changing the composition of the initial BaO/BaO2 oxides. The dependence of the superconducting transition temperature Tc on the lattice constant a (and, therefore, on the oxygen content) and of Tcmax and dTcmax/dp on n are convex upward up to n=4, 5. The maximum values always correspond to the Hg-1223 phase. Experimental Tcmax(n) curves for the phases with n=1–6 and dTcmax/dp curves for n=1–5 are compared with Anderson’s theory (the so-called RVB model). A general analysis of these results indicates that the mercury cuprates have an ideal structure for HTSC. The Hg-1223 phase is the “champion” in this ideal structure and the critical temperature corresponding to this phase (Tc=135 K) is the highest at atmospheric pressure.

This publication has 5 references indexed in Scilit: