Here are some sources of material properties for rare earth-based coated conductors.
The Robinson Institute collects and publishes critical current datasets on commercially-available HTS wire material to aid in the widespread adoption of HTS technologies. The data is distributed via the figshare repository where it is freely accessible to all.
Temperature-dependent thermal conductivity, heat capacity, and electrical resistivity of composing materials of HTS tapes (copper, silver, hastelloy, YBCO) in the range 30-80 K are available here for download (MS Excel format). The sources of these data can this found in this publication by S. Zou et al. and in the corresponding ArXiV pre-print.
A comprehensive set of data spanning an even wider temperature range (4-140 K) is available in Appendix G of J. van Nugteren’s master thesis.