【摘要】 介绍了一种用压埋法合成块状MgB2超导体的新方法。采用该方法得到的样品的临界温度可高达38 4K,与常规方法得到的样品的临界温度相近。对这种方法的合成工艺进行了探讨,发现烧结温度(Ts)和保温时间(t)对样品的临界温度影响很大。在相同的0 5h保温时间条件下,烧结温度在1073～1123K温区获得的样品临界温度最高。固定烧结温度(1123K),不同保温时间下获得的样品的临界温度随着保温时间的增加而降低。进一步对样品的剩余电阻率比(RRR)进行研究,实验结果表明随着RRR数值的增加临界转变温度下降。这可能与样品内过量的杂质有关。更多还原

【Abstract】 A new synthesizing method of the bulk superconductor of MgB2 is reported. The critical temperature of the sample is as high as 384 K, similar to those prepared by the conventional ways. The experimental results indicate that the sintering temperature (Ts) and soaking time (τ) affect the critical temperature greatly. The samples sintered between 1 073 K and 1 123 K in half an hour show higher critical temperature. At 1 123 K,　the critical temperature of samples decreases with increase of soaking time. The residual resistance ratio (RRR) is also investigated. The fact that the critical temperature decreases with increase of the value of RRR is associated with the excessive impurity.更多还原