EFFECTS OF SUBSTITUTIONS OF COPPER AT THE CHAIN SITE ON THE TRANSPORT AND MAGNETIC PROPERTIES OF YBa2Cu2(Cu1-xMx)O6+w

Abstract

We prepared polycrystalline samples of YBa 2 Cu 2( Cu 1-x M x) O 6+w, where M (=Sc, Cr, V, Fe, Al and Au) substitutes copper in the chain site, and measured their transport and magnetic properties. The substitution level x was 0.05 and 0.10 for each substituent. We determined the solubility of the different metals and the dependence of Tc, irreversibility lines and critical current density jc on M and x. An improvement of jc by a factor larger than 2 was obtained in the Fe-, Al-, Cr- and V- substituted materials. No improvement of the irreversibility line was obtained for any substituent.