Study on the Effect of Doping With Poly Zinc Acrylate Complex (PZA) on the Superconducting Properties of Bulk MgB2

In this work, the effect of doping with 5% to 20% Poly Zinc Acrylate complexes (PZA) on the MgB2 phase formation was studied. The changes of the lattice parameter and the amount of substituted Carbon, of the microstructure as well as the critical current temperature (T-c) and the critical current density (J(c)) of bulk MgB2 have been studied systematically. The DTA-TG and IR results show that the PZA was decomposed between 400 degrees C and 600 degrees C and the main decomposition products were carbonized polymers and ZnO. The lattice parameters a in all PZA doped MgB2 samples were decreased by different degrees, which indicates a gradual substitution of Carbon for the Boron sites in the MgB2 lattice structure. Comparing with the undoped sample, the J(c) values of all the doped samples were enhanced for about an order of magnitude under high magnetic fields. The J(c) value of MgB2 sample with 20% PZA doping and sintered at 800 degrees C for 1 h reached 0.8 x 10(4) A/cm(2) at 5 k and 8 T. TEM images reveled a considerable amount of second phase particles of similar to 5 nm size and high density dislocations were observed in MgB2 grains.