Fig. 4.

Electron-count–dependent superconducting transition temperatures in the high-entropy alloy compared with those in analogous simple solid solution and amorphous phases. Shown is a phase diagram of ${\left[\text{TaNb}\right]}_{1-x}{\left(\text{ZrHfTi}\right)}_x$ (purple squares are the $T_{\text{c}}$ and the blue line is a trend line) in comparison with transition metals and their alloys in the crystalline form (19) (yellow dashed line) and as amorphous vapor-deposited films (20) (red dashed line). The superconducting transition temperatures $T_{\text{c}}$ are plotted as function of the electron/atom ratio.