Lower critical magnetic field of lithium containing Bi2Sr2CaCu2O8+δ single crystals

Abstract

Lower critical magnetic field strength at 0 K, Hcl (T); T=0 K, has been evaluated on single-crystal Bi2.2Sr1.8Ca(Cu1-x, Lix)2Oy with 0≤x≤0.13 from d.c. susceptibility data. Significant change is noted between lithiuim-doped and undoped crystals: the value of Hcl (0) decreases with increasing lithium content when the magnetic field is applied to the direction parallel to the ab-plane, i.e. the cleaved crystalline plane, while the value remains constant when the direction of the field is perpendicular to the ab-plane. This could be attributed to the change in penetration depth along the c-axis, i.e. λc, with lithium incorporation. Analyses of diamagnetism versus temperature data were made, which exhibited no significant change in electron-transport mechanism with the variation of lithium content.