Based On The Study Of The Structure Of The Magnesium Diboride Josephson Junction

In March 2001,Japanese scientist reported superconducting properties of the simple binary metal compound MgB2. The critical transition temperature of the compound is 39 K, which is near or beyond the limits predicted by classical BCS theory for intermetallic compound superconductor. People wonder whether within the scope of BCS theory there exist some superconductors with higher critical transition temperature. The finding caused great concern of the international physics community.The structure of MgB2 is simple, its "grain boundary" is almost transparent to the superconducting current and it has higher critical current density.There is no weak connection problem. Therefore, MgB2 superconducting material may have a wide range of practical value, and have broad application prospects in the field of electronics. In addition, MgB2's has a larger coherence length. It may be relatively easy to produce the electronic devices based on the MgB2 Josephson junction in simple technology and good repeatability.The main work and conclusions are summarized as follows:(1)The preparation of MgB2 superconducting thin films by metal chemical vapor deposition(MOCVD) is proposed. Magnesium diboride(62HB) is used as the source of B, organic magnesium gas( ? P? MgC2) is used as the source of magnesium. In the basis of traditional chemical vapor deposition(CVD) system, we increased the gas channel for organic magnesium source, so that the organic magnesium gas is heated to decompose into Mg atoms and some functional groups, and then Mg atoms react with B and deposited as MgB2 film on the substrate.(2)According to the experiment data of MgB2/B/MgB2 Josephson junction prepared in our laboratory, a circuit model is established in Multisim, the simulation results comply with the measured property of the junctions. Based on the theoretical analysis, transient simulation for rapid single flux quantum(RSFQ) splitters are conducted.(3)The MgB2-B-MgB2 Josephson junction was successfully prepared by thecrystal B film, and it was proved that the crystal form of B is reasonable and feasible for the insulating layer of Josephson's junction.