Theory Research Of Doping MgB₂

The development of low temperature physics and superconductivity and the method of obtaining low temperature simply were introduced in the dissertation at first. The characteristics and superconductors of MgB₂ were also introduced at the same time. Then, the development of the DFT, the conception and development of electro-negativity and hardness were introduced mainly. Electro-negativity and hardness of doping MgB₂ systems, the relation of specific heat and energy gap were calculated.The results showed that: The doping MgB₂ systems, which with equalized hardness value between 4.20 and 4.30 as well as electro-negativity value between 3.95 and 4.025, had good superconductivity. And it gave prediction of the biggest composition ratio for doped elements. It gave a good reference to conduct the study on the superconductivity of doping MgB₂ systems with the value of hardness and electro-negativity, especially gave a good reference on theory for the doped elements and doping ratio in experiments.At last, some calculation on special heat was explored. The result was consistent with experiment.