Lead-mercury-based superconductors - the 1212-cuprate <script type="math/tex">Pb_{0.7}Hg_{0.3}Sr_{2+x}Ca_{0.7}Nd_{0.3-x}Cu_{2}O_{7-\delta}</script> and the new oxycarbonate <script type="math/tex">Pb_{0.7}Hg_{0.3}Sr_{4}Cu_{2}CO_{3}O_{7}</script>

Martin, C.; Hervieu, M.; Huvé, M.; Michel, C.; Maignan, A.; Van Tendeloo, G.; Raveau, B.

doi:10.1016/0921-4534(94)90109-0

Title

Lead-mercury-based superconductors - the 1212-cuprate $Pb_{0.7}Hg_{0.3}Sr_{2+x}Ca_{0.7}Nd_{0.3-x}Cu_{2}O_{7-\delta}$ and the new oxycarbonate $Pb_{0.7}Hg_{0.3}Sr_{4}Cu_{2}CO_{3}O_{7}$

Author

Martin, C.

Hervieu, M.

Huvé, M.

Michel, C.

Maignan, A.

Van Tendeloo, G.

Raveau, B.

Abstract

A new superconducting mercury oxycarbonate, Pb0.7Hg0.3Sr4Cu2CO3O7, has been synthesized. This tetragonal phase (a = 3.824 angstrom, c= 16.468 angstrom) consists of an intergrowth of two nonsuperconducting compounds, Sr2CuO2CO3 and Pb0.7Hg0.3Sr2CuO5. It exhibits after optimization a critical temperature of 70 K, with a sharp transition and a superconducting volume fraction of 50%. Its behavior can be compared to that of thallium oxycarbonates previously isolated. This study is completed by a reinvestigation of the 1212 cuprate of the system Hg-Pb-Sr-Ca-Nd-Cu. A superconducting phase with the 1212 structure, similar to that previously obtained but with a significantly different composition, Pb0.7Hg0.3Sr2+xCa0.7Nd0.3-xCu2O7, has been obtained, with a T(c onset) of 100 K. The behavior of the latter is compared with other lead-based 1212 cuprates.

Language

English

Source (journal)

Physica: C : superconductivity. - Amsterdam, 1988, currens

Publication

Amsterdam : North-Holland , 1994

ISSN

0921-4534 [print]

1873-2143 [online]

DOI

10.1016/0921-4534(94)90109-0

Volume/pages