Superconductivity:
Resistance vs. Temperature

Clear["Global`*"]; SetDirectory[NotebookDirectory[]];
DateString[]

Fetch a file but only select entries with a reasonable temperature.  (Sometimes the probes were temporarily bumped or mixed up, and sometimes the run ran on far too long to high temperatures.)

getRvsT[file_] := Select[Import[file, "Table"], 70 <= #[[1]] <= 150 &]

BSCCO Samples

bsccofiles = FileNames["BSCCO*"]

ListPlot[Map[getRvsT[#] &, bsccofiles], PlotStyle -> PointSize[Small], PlotLegends -> bsccofiles, LabelStyle -> Larger, AxesLabel -> {"T (K)", "R (Ω)"},  PlotRange -> All, ImageSize -> Scaled[0.8]]

YBCO Samples

ybcofiles = FileNames["YBCO*"];

ListPlot[Map[getRvsT[#] &, ybcofiles], PlotStyle -> PointSize[Small], PlotLegends -> ybcofiles, LabelStyle -> Larger, AxesLabel -> {"T (K)", "R (Ω)"},  PlotRange -> All, ImageSize -> Scaled[0.8]]

Comparing Select BSCCO and YBCO Samples

cmps = {"YBCO-3-20250505.txt", "BSCCO-6-20250502.txt"};

ListPlot[Map[getRvsT[#] &, cmps], PlotStyle -> PointSize[Small], PlotLegends -> cmps, LabelStyle -> Larger, AxesLabel -> {"T (K)", "R (Ω)"},  PlotRange -> All, ImageSize -> Scaled[0.8]]