Influence of Ho-Doping on the Electromagnetic Field-Dependent $E$–$J$ Characteristics of (Bi,Pb)-2212 Superconductor

The magnetic field ($B$ ) dependence of electric field versus transport current density ($E\hbox{–}J$ characteristics) of $\hbox{Bi}_{1.6}\hbox{Pb}_{0.5}\hbox{Sr}_{2-{x}}\hbox{Ho}_{x}\hbox{Ca}_{1.1}\hbox{Cu}_{2.1}\hbox{O}_{8+\delta}$ superconductor was studied for $x$ from 0.000 to 0.200. The behavior of supercurrent flow under magnetic fields in Ho-doped (Bi,Pb)-2212 is explained using thermally activated flux-creep. The $n$ -value and characteristic pinning energy ( ${U}_{c}$) estimated from $E\hbox{–}J$ characteristics show that at applied fields, the flux-lines in Ho-doped samples are in the glass-state. A correlation is observed between $n$ -index and ${J}_{c}$ of doped samples. The highly enhanced critical current density (${J}_{c}$) and $n$-index in both self- and applied-fields due to Ho-doping is of great scientific and technological significance.