Defective structure in the high-Tc superconductor Hg-1234

Samples with different fractions of structural modulation were synthesized in order to study the effect of a defective modulated structure on the critical temperature Tc of Hg-1234. Electron microscopy revealed the existence of modulated and unmodulated Hg-1234 structures in these samples. Measurements of critical temperature Tc on these samples revealed that the structural modulation significantly suppresses the Tc. For the Hg-1234 sample without the structural modulation, the Tc was found to be close to the highest Tc for the Hg-1223 phase.