Experimental evidence for high-temperature organic fractional superconduction in cholates.

Experimental data are presented indicating that six organic compounds (homologous cholates) possess properties associated with high-temperature superconductivity. From magnetic and electrical measurements it is deduced that behavior resembling superconductivity occurs below characteristic transition temperatures in small domains included in the insulating bulk of the sample material, which is therefore designated a fractional o Type III superconductor. The six cholates exhibit this superconductivity below transition temperatures ranging from approximately 7.5 degrees K for sodium dioxycholate to 277 degrees K for sodium cholanate. It has been further established that the diamagnetic shifts with temperature cannot be attributed to ferrielectric, ferroelectric, or capacitive effects. Below the transition temperatures the cholates behave like perfect diamagnets, susceptible to forceful repulsion by a moderate magnetic field. Observed in a sensitive susceptometer, magnetic flux trapped in the material gave rise to a 3% remnant magnetic moment. Studied in particular detail were sodium cholate, sodium deoxycholate, and lithocholic acid, which showed transition temperatures of 30 degrees K, 60 degrees K, and 130 degrees K respectively. The hydrophobic property of the closed four-ring structure (R-group) common to the cholates, along with the hydrophilic property of the carboxylate group (S-group), are responsible for domain formation. Because of those properties, clustering of the S-groups occurs when traces of water are introduced into the material. When followed by slow desiccation, the clusters form the micelles constituting the superconducting domains.