The microstructure and electrical properties of thin films processed at low temperatures

Abstract

thin films on (001) with excellent alignment suitable for microwave applications at 77 K have been fabricated using an ex situ anneal step in argon atmospheres at temperatures of . Surface resistance values as low as 400 (79 K, 10 GHz) and large-area critical current densities up to (77 K) have been achieved. In order to understand the relationship between the microstructure and electrical properties the films have been characterized by a variety of techniques, but especially transmission electron microscopy and allied methods. Microstructural features such as a-axis oriented grains, secondary phase particles, grain boundaries and surface outgrowths (especially of non-superconductor phases) have been found to have a significant effect on the surface resistance.

Synthesis and microwave properties of TI2Ba2CaCu2O8 superconducting films grown by MOCVD

“…The reaction atmosphere is controlled by mixing different flows of oxygen and argon gasses. Preliminary data on the correlation of oxygen partial pressure and temperature [12] on the formation of Tl-Ba-Ca-Cu-O phases clearly indicate that lower oxygen partial pressure requires lower annealing temperatures [13]. The present films were annealed at a temperature of 820 • C for 40 min using an oxygen partial pressure of 0.7 × 10 5 Pa.…”

A metal-organic chemical vapor deposition approach to double-sided Tl2Ba2Ca1Cu2O8superconducting films on LaAlO3(100) substrates

“…Therefore, the development of low-cost processes represents a crucial step for large-scale applications. To date, efforts to produce single-sided (SS) [9][10][11][12] and double-sided (DS) [13][14][15] thin films of Tl-based superconductors have been largely focused on physical vapor deposition (PVD) techniques.…”

Growth of Tl2Ba2CaCu2O8 superconducting thin films on curved substrates for metamaterials applications

“…Plate C is an a-axis needle aligned with c-axis along the axial direction of the cylinder. These needles are also commonly observed in Tl-2212 films grown on planar substrates [22].…”