利用混合物理化学气相沉积法(hybrid physical—chemical vapor deposition,HPCVD)可以制备出高性能的MgB2超导薄膜,再对薄膜进行钛(Ti)离子辐照处理.经过辐照处理后的样品被掺入了Ti元素,与未处理的干净MgB2样品相比,其超导转变温度没有出现大幅度的下降,而在外加磁场下的临界电流密度得到了明显的提高,同时样品的上临界磁场也得到了提高.在温度5K,外加垂直磁场为4T的情况下,Ti离子辐照剂量为1×1013/cm2的样品的临界电流密度达到了1.72×105A/cm2,比干净的MgB2要高出许多,而其超导转变温度仍能维持在39.9K的较高水平.
High-quality MgB2 films are fabricated via hybrid physical-chemical vapor deposition (HPCVD) and irradiated by Ti ions. Com- pared with the unirradiated film, the Ti-irradiated MgB2 film shows a high critical current density (Jc) in magnetic field and also a high upper critical field (He2), while the superconducting transition temperature (Tc) does not decrease significantly. The Ti-irradiated film with a best fluence at 1×1013/cm2 shows a high Jc of 1.72×105 A/cm2 in 4 T perpendicular field at a temperature of 5 K and a moderately decreased Tc at 39.9 K.