Single domain GdBCO bulk superconductors have been successfully fabricated by the modified top seeded infiltration and growth technique(TSMIG).Instead of the traditional solid source Gd2BaCuO5, the Gd2O3 +xBaCuO2 (x=1.0, 1.2, 1.4, 1.6 1.8, 2.0, 2.2, 2.5) was used as solid source(SS).The liquid source(LS) were composed of Y2O3 , CuO and BaCuO2 instead of the traditional one made by GdBa2Cu3O7-y and Ba3Cu5O8. The morphology, microstructure and superconducting properties of the products were investigated in detail. The results indicate that when the ratio x range from 1.0 to 2.5 the samples can grow into single domain GdBCO bulk superconductors . The levitation force of the products increases first and then decreases with the increasing of x. The largest levitation force of 33 N is obtained in the products with x=1.8, which perform better than the same size bulk superconductor made by Gd2BaCuO5. The microstructure of the sample indicates that nano-scale particles(2~450 nm) exist in the GdBCO.Because the new solid source is used in the MTSIG,only BaCuO2 precursor powders should be prepared for the whole MTSIG flow.Thus the efficiency of fabricating GdBCO superconductors is considerably improved and the time of fabricating GdBCO superconductors is reduced.

single domain GdBCO bulk superconductors；top seeded infiltration and growth technique；solid source；magnetic levitation force