COMPARATIVE STUDY OF ELECTRICAL RESISTANCE OF DISC-SHAPED COMPACTS FABRICATED USING CALCINED CLAMS SHELL, PERIWINKLE SHELL AND OYSTER SHELL NANOPOWDER.

In this investigation, Clam, Periwinkle and Oyster shells were separately treated, calcined and ball-milled into nano powder. Each nano powder material was fabricated into disc of various lengths in three replicates. In each case, the electrical characteristics of the discs were determined. Electrical resistivity values obtained for test samples developed from Clam, Periwinkle and Oyster shells were found to be (6.024 ± 0.009) x 10⁵ Ωm, (6.823 ± 0.030) x 10⁵ Ωm, and (4.916 ± 0.007) x 10⁵ Ωm respectively at a temperature of (25.0 ± 1.0oC). Also, electronic activation energy values were found to be 0.68eV, 0.61eV, and 0.76eV, while thermal sensitivity index values were obtained as 7850K, 7058K, and 8814K respectively for the samples fabricated from the shells of Clam, Periwinkle, and Oyster. The shell samples exhibit a negative temperature coefficient of resistance with values of - 8.83%/K, -7.94%/K and -9.92%/K for Clam, Periwinkle and Oyster shells respectively. These results provide data base on the electrical characteristics for the shells. It can be adjudged from the results that the shells are potential raw materials for NTC thermistor production. They have high sustainability and can be considered to be economically cheap since they are discarded as waste. [ABSTRACT FROM AUTHOR]