The crystal structure and the superconductivity for samples Mg(B 1-x C x) 2 (0 ≤ x ≤ 0.09) prepared by a hybrid microwave synthesis have been investigated.The starting material B 10 C is also obtained by using the microwave method.The carbon can distribute uniformly in the Mg(B 1-x C x) 2 samples because boron and carbon are mixed on an atomic scale in the staring material B 10 C.The dependences of both lattice parameters and superconducting transition temperature T c on carbon content accord with those reported in the literature.The upper critical field H c2 at 20 K can be enhanced from about 4.3 T for x=0 to 10 T for x=0.05.The critical current density J c of Mg(B 0.95 C 0.05) 2 is 1.05 × 10 4 A/cm 2 at 20 K and 1 T.
