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利用混合物理化学气相沉积法(HPCVD)在MgO(111)衬底上制备了干净的MgB2超导超薄膜.在背景气体压强、载气氢气流量以及沉积时间一定的情况下,改变B2H6的流量,制备得到不同厚度的系列MgB2超导薄膜样品,并测量了其超导转变温度Tc,临界电流密度Jc等临界参量.该系列超导薄膜沿c轴外延生长,表面具有良好的连接性,且有很高的超导转变温度Tc(0)≈35—38K和很小的剩余电阻率ρ(42K)≈1.8—20.3μ.cm.随着膜厚的减小,临界温度变低,而剩余电阻率变大.其中20nm的样品在零磁场,5K时的临界电流密度Jc≈2.3×107A/cm2.表明了利用HPCVD在MgO(111)衬底上制备的MgB2超薄膜有很好的性能,预示了其在超导电子器件中广阔的应用前景.
A clean MgB2 superconducting ultrathin film was prepared on the MgO (111) substrate by hybrid physical and chemical vapor deposition (HPCVD). The flow rate of B2H6 was changed under the conditions of the background gas pressure, the carrier gas hydrogen flow rate and the deposition time. The superconducting transition temperature (Tc) and critical current density (Jc) of superconducting thin films with different thickness were obtained, and the superconducting thin films were epitaxially grown along the c-axis with good connectivity on the surface The high superconducting transition temperature Tc (0) ≈35-38K and very small residual resistivity ρ (42K) ≈1.8-20.3μ.cm.With the decrease of the film thickness, the critical temperature becomes lower, while the residual resistivity Which shows that the critical current density at 20K in the magnetic field at 5K is Jc≈2.3 × 107 A / cm 2, indicating that the MgB2 ultrathin films prepared by HPCVD on the MgO (111) substrate have good performance, Its superconducting electronic devices in the broad application prospects.