Simulated sputtering yields of niobium and its oxides, and experimental data on plasma and electrolytic plasma polishing of niobium samples.

`sputteringyield.xlsx` contains sputtering yield data for niobium and its oxides calculated using SRIM software; `untreated Ar Ar+O2 sa sq sz.opju` presents surface roughness results for niobium samples that were untreated, or treated via plasma sputtering (without bias voltage) using pure argon or an argon-oxygen mixture; `150V-450V Sa Sq Sz.opju` shows surface roughness results for niobium samples treated via plasma sputtering in pure argon at various bias voltages; `450V Ar Ar+O2 sa sq sz.opju` displays surface roughness measurements for samples treated via plasma sputtering in pure argon and argon-oxygen mixtures at a 450V bias voltage; `200-300V PEP.opju` provides surface roughness results for niobium samples treated via electrolyte plasma polishing at different voltages; `EC wt%.opju` presents surface roughness results for samples treated via electrolyte plasma polishing at different electrolyte concentrations; all roughness data were obtained using a 3D optical profilometer. `MRR and Curent vs voltage.opju` shows the etching rate and current variations for niobium samples during electrolyte plasma polishing at different voltages; `MRR and Curent vs wt.opju` shows the etching rate and current variations at different electrolyte concentrations (both datasets were obtained directly during the experiments); `before and after PeP XRD.opju` contains XRD patterns of niobium samples before and after electrolyte plasma polishing; `precipitates XRD.opju` contains XRD patterns of the precipitates formed after electrolyte plasma polishing (all XRD data were obtained using an XRD instrument).