Synthesis and characterization of HgBa(2)RCu(2)O(6+delta) (R=Eu, Gd, Ho, Er, Tm, Yb and Y)

Compounds with the general formula HgBa(2)RCu(2)O(6+delta) (Hg-1212 phase, R=Eu, Gd, Ho, Er, Tm, Yb and Y) were synthesized by solid state reaction. The influence of synthesis conditions on the phase composition of these samples was investigated. X-ray powder and electron diffraction data have shown that all synthesized compounds are isostructural with the Hg-1212 phases containing rare earth elements of larger ionic radius, already published in literature. Different thermal annealings performed on the samples showed the impossibility of substantially changing the oxygen content of the synthesized compounds. Measurements of the temperature dependence of the magnetic susceptibility showed no diamagnetic signal down to 12 K.