Syntheses and characterization of polynuclear metal complexes related to a chemical precursor system for the YBa2Cu3O7–x superconductor

Abstract

A chemical precursor system for the YBa₂Cu₃O_7–x superconductor has been investigated. From [Cu₂(O₂CCH₃)₄(H₂O)₂], Ba(O₂CCH₃)₂, and [Y(O₂CCH₃)₃(H₂O)₄] as starting materials and acetic acid and 1,3-bis(dimethylamino)propan-2-ol (Hbdmap) as the cross-linking agents, the YBa₂Cu₃O_7–x, powder sample obtained had an onset superconducting temperature of 92 K. Polynuclear metal complexes related to this system have been characterized. Thus [{Cu₄(bdmap)₂(O₂CCH₃)₆(H₂O)₆}_n], [LaCu₂(bdmap)₃(O₂CCF₃)₄] and [Cu₃(bdmap)₃(O₂CCF₃)₂]₂[Y₂(bdmap)₂(O₂CCF₃)₆] have been characterized structurally and their thermal and magnetic properties have been studied. The compounds decompose to the corresponding oxides when heated under an oxygen atmosphere.