Suppression of superconductivity in a molecular charge transfer salt by changing guest molecule: β″-(BEDT-TTF)4[(H3O)Fe(C2O4)3](C6H5CN)x(C5H5N)1−x.

SQUID magnetometry and transport measurements combined with crystal structure refinement have been used to examine the variation in superconducting properties (Tc and Meissner fraction) in the molecular superconductor β″-(BEDT-TTF)4[(H3O)Fe(C2O4)3]·C6H5CN on replacing the C6H5CN guest molecule with pyridine (C5H5N). Up to approximately 65% pyridine substitution there is only a small decrease in Tc and Meissner fraction but above that the superconductivity is suppressed. [ABSTRACT FROM AUTHOR]