Transport Properties of Chalcopyrite (CuFeS2) in a Wide Range of Temperatures

We studied the transport properties of American chalcopyrite ore in a wide range of temperatures. Electrical resistivity of the sample is studied both at low (77-300K) and high temperature (300-450K), thermoelectric power from 300K to 400K, and AC magnetic susceptibility in the temperature range 77-300K. The electrical resistivity measurement shows step wise increasing conductivity with increasing temperature that is quantum conductance is observed. Thermoelectric power measurement in the temperature range 300-400K shows a wriggling effect. Susceptibility measurement in the temperature range 77-300K shows a positive peak at 80K, hence a ferromagnetic response and a negative peak at 90K shows a diamagnetic response. Later on, when increasing the temperature up to 300K, the susceptibility is positive and almost remains constant, which reveals an antiferromagnetic behavior in the temperature range 150-300K. The characterization of the sample (American chalcopyrite) is done by using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD) analysis. The SEM analysis shows the surface of the chalcopyrite sample with two different phases. The EDS analysis reveals that the sample contains copper (Cu) 19%, iron (Fe) 23% and sulfur (S) 20% by atomic percent, along with some other impurities. On the basis of this composition we suggest that chalcopyrite is a semiconductor as it contains oxygen (O), carbon (C) and sulfur (S) as impurity elements. The XRD analysis shows that the sample has a body-centered tetragonal structure.