Fluctuation-Induced Conductivity of Carbon in Glucose-Doped MgB2 Superconductor

Fluctuation-induced conductivity (FIC) of glucose as a carbon-doped MgB2 sample was investigated in the presence of a magnetic field in the range of 0-14T. Different concentrations (0-8%) of glucose-doped MgB2 samples were prepared using planetary dry ball milling and then employed standard solid-state reaction method on these samples. The prepared samples were characterized by X-ray diffractometer. The resistive transition broadening of all the samples becomes wider as the magnetic field was increased. The results of doped MgB2 explained in terms of temperature derivative of the resistivity, d with temperature. The mean field transition temperature () has been taken from the peak of the temperature derivative of resistivity plot for different doped samples. It is clear that of d shifted to lower temperature region as we increase the magnetic field of the doped samples. Lawrence and Doniach model has been employed for the present study. The variation of FIC against inverse reduced temperature ( for different concentrations of glucose-doped MgB2 samples was measured with varying applied field. The enhancement of coherence length observed as we decrease the value of T (c) and for 5 and 8% C in glucose-doped MgB2 samples when subjected to a different field.