Bonding and Mössbauer Isomer Shifts in (Hg, Pb)‐1223 Cuprate

Abstract

By using the chemical hood theory of dielectric description. the chemical bond parameters of (Hg, Pb)-l223 were calculated. The &ts show that the (&I , Sr)-O and (3-0 types of bond have higher ionic character, while the Cu-0 and (Hg, Pb)-O types of bond have more covalent charader. Mtkbawr isomer shiffs of nFe and %n do@ in (Hg, pb)-l223 were calculated by using the rhemical environmentsl fador, he, defined by covalency and electronicpolarizability. FourvalencestatetinandthRereleneeiron sites were identi6ed in nFe and luSn doped (Hg, Pb)-l223 superconductor. It can be collchded that all ofthe Fe atom substitute the Cu at square phmr Cu(1) site, whereas Sn prefers to substitute the square pymmidaI Cu(2) site.