Effect of pressure and temperature on the resistivity of Nd0.97Ca0.03Ba2Cu3O7−δ

The effect of pressure and temperature on the electrical resistivity of the composition-controlled Nd0.97Ca0.03Ba2Cu3O7−δ superconductor have been studied. Electrical resistivity measurements were carried out by a four-probe technique using a Bridgman opposed anvil high-pressure device and the high-temperature measurements were done using a heating coil arrangement. The measurements were done up to a pressure and temperature of 8 GPa and 523 K, respectively. The structure of the sample was confirmed by the theoretical calculation of the X-ray diffraction intensities. A gradual decrease in the electrical resistivity with increase of pressure was observed. The effect of pressure on the bonds causing the decrease in the resistivity has been confirmed by X-ray diffraction measurements. The temperature effect causes an upward shift in the electrical resistivity in the observed range of pressure.