【摘要】 我们测量了 T1-Ba-Ca-Cu-O 高温超导样品在低磁场下的磁化率和电阻与温度的关系;观察到样品具有两个超导主相,T_c 分别为117K 与104K;估算出该样品在77K 下的下临界场H_c1大约为480G.样品的迈斯纳效应和磁屏蔽的测量结果表明,该样品的磁屏蔽效应很小.在外加低磁场下测量了样品的临界电流,研究了,I_c-H 关系,发现在30G 以下磁场范围内的实验结果与超导颗粒之间是无规并联的约瑟夫森弱连接的理论结果符合较好.更多还原

【Abstract】 The superconductivity of Tl-Ba-Ca-Cu oxide and its resistivity upon temperature have been measured under the low magnetic field.It has been observed that there are two main superconducting phases (117 K and 104 K) in the sample.The lower critical field Hcl is determined to be about 480 G at 77 K.The measurements of Meissner effect and the shielding effect show that the magnetic shielding of the sample is very small.The relation between Ic and H has also been measured and the experimental data are in good agreement with a parallelly conec-ted Josephson weak-link model below about 30 G,更多还原