Magnetron sputtering of Superconducting Multilayer Nb3Sn Thin Film

sample with the Nb sputtering current of 1.0A has the great peak of the Nb crystalplane, but all of the peaks of all samples are smaller than that of 5 minutes annealing.The cubic edge length of the Nb 3 Sn thin film on the sapphire and Nb arecalculated and shown in Fig.3.55. The cubic edge length of the thin film depositing onthe sapphire decreases with the increasing of the Nb sputtering current. But the curvesof the Nb sample when the annealing time is different.3.4 ConclusionThe T c of the Nb 3 Sn multilayer deposited on the sapphire and annealed by thelamp is about 17K and the RRR of that is about 5. This result is not good enough,especially for the RRR. So we need more investigation, such as changing theproceeding gas pressure and so on.The result of Nb 3 Sn multilayer deposited on Nb and annealed by the inductor isalso not good enough, but the multilayer without cover layer of Nb seems to have thebetter performance, in spite of the peaks of the Nb crystal plane of this kind of filmare higher than the other kinds of. So the next investigation should include thechanging the proceeding gas pressure and comparing the thin film between with andwithout the cover layer.The reason of that multilayer deposition without the over layer is needed forfurther investigation is that when we deposit the thin film of Nb 3 Sn on the acceleratorcavity, it is impossible to use two magnetrons as shown in our experiment, and it ispossible to use a post target [34] for thin film deposit, and then it is some complicatedto change another target if we want to deposit the Nb cover layer.In the conclusion, there are four jobs needed to do in future: the first job is toresearch the effect on the thin film of the proceeding gas pressure; the second job is toresearch the effect of the annealing time of the inductor; the third job is to research theeffect of the Nb over layer; the fourth job is to research the deposition on the cavity.72