铊系单晶的超导电性及压力增强效应

Superconductivity And Its Pressure Enhance Effect of Tl Single Crystal

采用自助熔剂方法生长单晶，得到了T1－2223相和T1－1223相样品，交流磁化率测试结果表明，它们的抗磁起始转变温度分别为106K和102K。利用Bridgeman对顶砧对样品作了高压研究，通过加压，它们的超导转变温度分别比环境压力下升高了9K和14K，最大的压力效应系数dTc／dP分别为2．4K／Gpa和2．5K／Gpa，超导转变温度Tc和压力P之间近似呈抛物线关系，压力P和载流子浓度之间存在有线性关系，两者的较高的超导转变温度是和它们的结构分不开的。

A self flux method was used for growing single crystal. We obtained T1 - 2223 and Tl -1223 phase samples- The Ac magnetic susceptibility shown that their antimagnetic transition temperature is 106K and 102K respectively. The sample is investigated at high pressure by using Bridgeman vertical harmmering block. By raising pressure, their superconducting tran-sition temperature is increased by 9K and 14K respectively compared with the ambient temperature. The maximum pressure effect coefficient(dTc/dp) is 2. 4K/GPa and 2. 5K/GPa respectively. Superconducting transition Tc and pressure P fits close to the relation of parabola. The pressure P and carrier density has a linear relation. The higher superconducting transition temperature of two samples are connected with their structutes.