Effect of additional magnetic material Ni on structure and magnetic properties Eu_2-xCe_xCu_0.99Ni_0.01O_4+α-δ

Superconductors are materials with the unique characteristics when the temperature of the material is below its critical temperature, namely zero resistivity. There are many superconducting phenomena that need to be explained theoretically. One of them is the effect of addition of impurities on the physical properties of superconducting materials. In this study, the addition of 0.01 Ni magnetic impurities in the Eu2-xCexCuO4+α-δ material has been carried out to form the structure Eu2-xCexCu0.99Ni0.01O4+α-δ, in an under-doped area with a concentration of Ce (x) = 0.09 and 0.10. Material synthesis was carried out by the solid reaction method with prefire at 900 °C for 20 hours, sintering at 1,000 °C for 16 hours, and annealing at 900 °C for 10 hours by flowing argon (Ar) gas. The XRD measurements were carried out to investigate the crystal structure, while the magnetic properties were carried out by SQUID measurement at temperature of 2 K to 30 K. From the XRD measurements, it was found that the crystals formed had a tetragonal crystal structure T' which was indicated by the appearance of two main peaks with Miller indices (103) and (110), lattice parameter a is 3,904 A in both samples, lattice c is 11.8752 A and 11.9738 A for the concentrations of Ce (x) = 0.09 and 0.10. The volume of unit cells obtained were 181.0178 A3 and 181.0244 A3 with the bond distance between Cu-O of 1.9521 A and 1.9523 A. It was also obtained that the crystal size were 86.2604 nm and 91.6735 nm. From the SQUID measurement, it was found that the material Eu2-xCexCu0.99Ni0.01O4+α-δ has paramagnetic properties. The value of the effective magnetic moment was decreased by reducing the addition of Ni impurities of 0.0057 and 0.0051.