Abstract
Two series of Hg-based oxides (Hg0.7Mo0.3)Sr-2(Ca1-xRx)Cu2Oz (R = Nd and Pr, 0.2 less than or equal to x less than or equal to 0.7) have been synthesized. Electrical-resistivity measurements show that these compounds are superconductors with maximum onset T-c of 107 and 102 K for Nd- and Pr-containing samples, respectively. The neutron powder diffraction experiments on both as-prepared and O-2-annealed samples of R = Nd revealed that the O(3) site at the HgOdelta sheets are fully occupied and shifted towards the Hg/Mo site to form Mo-O bonds.