Pressure effect on the superconductivity of Ca1−xLaxFeAs2 (x = 0.18) single crystal
Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University - Nanjing 211189, China
Received: 13 October 2014
Accepted: 22 January 2015
Two steps of resistance decreases were observed in cooling Ca1−xLaxFeAs2 (x = 0.18) single crystal under high-pressure condition. The temperature T1 at which the high-T decrease takes place shows little pressure dependence. On the other hand, the low-T decrease was ascribed to a superconducting transition for the zero resistance. With elevating pressure P, both the onset and zero-resistance transition Tc's first increase and then decrease continuously, showing a dome-shape pressure phase diagram with an optimal pressure around 1.19 GPa. The positive-pressure effect of the superconducting transition demonstrates the possibility of exploring higher Tc's in the present material.
PACS: 74.62.Fj – Effects of pressure / 74.70.Xa – Pnictides and chalcogenides / 74.25.F- – Transport properties
© EPLA, 2015