Persistent Currents in Sodium Cholate.

摘要

The object of this work was to obtain experimental evidence that sodium cholate had superconducting properties. It was tested by means of a Superconducting Susceptometer which is described as a thin film superconducting magnetometer (SQUID). The material was tested and found capable of carrying an indefinitely persistent current over macroscopic distances at temperatures ranging from 4-30K. The magnetic susceptibility was measured from 24-36K at 0.5K intervals and a discontinuity was found between 28 and 30K with a peak at 29K. The material is however, a bulk insulator. When this evidence is considered in the light of similar findings by tests performed by the Schwawlow and Devlin frequency change method relationships previously found for (T sub c) vs e/a, (T sub c) vs 1/the square root of M (the isotope effect), (T sub c) vs (theta sub d), and the discontinuity found at 30K on a (c sub p) vs T curve the evidence for presence of superconductivity is very strong. The high resistence could possibly be attributed to a low concentration of conduction electrons coupled with an off center position of the sodium ion when considered in relation to the GL sandwich theory.