Critical current density and ac harmonic voltage generation in $YB{a}_{2}C{u}_3{O}_{7-\delta }$ thin films by the screening technique

Abstract

The temperature and field dependence of harmonics in voltage $V_n=V_n^{\prime }-iV{"}_n$ using the screening technique have been measured for $\mathrm{Y}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ superconducting thin films. Using the Sun model we obtained the curves for the temperature-dependent critical current density $J_c(T)$. In addition, we applied the criterion proposed by Acosta et al. to compute $J_c(T)$. Also, we made used of the empirical law $J_c\propto (1-T/T_c{)}^n$ as an input in our calculations to reproduce experimental harmonic generation up to the fifth harmonic. We found that most models fit well the fundamental voltage but higher harmonics are poorly reproduced. Such behavior suggests the idea that higher harmonics contain information concerning complex processes like flux creep or thermally assisted flux flow.

2 pages, 2 figures

Cited by in corpus (3)

• Design and construction of a desktop AC susceptometer using an Arduino and a Bluetooth for serial interface
• Study of higher-order harmonics of complex ac susceptibility in $Y{B}_2{C}_3{O}_{7-\delta }$ thin films by the mutual inductive method
• In situ comparison of the critical current density in $YB{a}_{2}C{u}_3{O}_{7-\delta }$ thin films measured by the screening technique under two criteria