Resistivity, Hall effect, and anisotropic superconducting coherence lengths of HgBa₂CaCu₂O₆ thin films with different morphology

Thin films of the high-temperature superconductor HgBa$_2$CaCu$_2$O$_{6+\delta}$ have been prepared on SrTiO$_3$ substrates by pulsed-laser deposition precursor and subsequent annealing in mercury-vapor atmosphere. The microstructural properties such can vary considerably analyzed x-ray diffraction atomic force microscopy. Whereas resistivity is significantly enhanced samples with coarse-grained structure, Hall effect shows little variation. This disparity discussed based models for transport granular materials. We find that, despite morphological variation, all similar superconducting properties. critical temperatures $T_c \sim 121.2$ K $\dots 122.0$ K, resistivity, data indicate that are optimally doped. analyses order parameter fluctuations zero finite magnetic fields yield in-plane $\xi_{ab}(0) 2.3$ nm 2.8$ out-of-plane $\xi_{c}(0) 0.17$ $ \dots 0.24$ Ginzburg-Landau coherence lengths at temperature. measurements provide estimates carrier scattering defects normal state vortex pinning inside grains.