Pinning force estimation method based on a vortex position analysis

R. F. LUCCAS; ET AL.

Natal

Workshop; 16th International Workshop on Vortex Matter in Superconductors VORTEX2017; 2017

IIP-UFRN

Vortex positions at the flux line lattice (FLL) carry on with huge amount of information. Interactions of vortices with material defects as well as other vortices are responsible of each vortex positions at the system. A proper analysis of these positions could show us local information of material properties through the interaction energy that locate vortices at particular places.We present here a model able to associate a potential energy to each vortex position at the FLL[1]. This potential energy is directly related to local pinning energy of the material. Results coming from Bitter decoration experiments on YBa2Cu3O7-d (YBCO) single crystals and thin films with different kind of defects are shown. Applying our model, we observe a pinning energy at least 3 times higher for thin films in comparison with pinning energy quantifies for single crystals. Also, comparing surface linear defects generated artificially on samples, our model points out a strong pinning energy, at least twice, for nano-indented defects in comparison with ion irradiated defects.Finally, a further basic emulation of vortex positions, formulated in accordance with our model, allows to perform a special analysis of surface linear defects artificially generated. In this way, we were able to estimate a minimum pinning energy for nano-indented defects of 3 times the interaction vortex energy working at low magnetic fields, according to Bitter decoration experiments on YBCO single crystals.[1] R. F. Luccas, et al., "Vortex energy landscape from real space imaging analysis of YBa2Cu3O7 with different defect structures", Physica C: Superconductivity and its applications 505, 47 (2014).