| DUT-67(Hf) proton conductivity at 30 deg C, 68% RH | 1.31e-07 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 30 deg C, 75% RH | 1.42e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 30 deg C, 85% RH | 2.21e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 30 deg C, 93% RH | 3.35e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 30 deg C, 98% RH | 0.000694 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 30 deg C, 98% RH-D2O | 0.000183 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 40 deg C, 68% RH | 4.32e-07 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 40 deg C, 75% RH | 2.23e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 40 deg C, 85% RH | 2.61e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 40 deg C, 93% RH | 5.77e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 40 deg C, 98% RH | 0.000759 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 40 deg C, 98% RH-D2O | 0.000204 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 50 deg C, 68% RH | 7.47e-07 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 50 deg C, 75% RH | 4.81e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 50 deg C, 85% RH | 6.91e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 50 deg C, 93% RH | 8.1e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 50 deg C, 98% RH | 0.000881 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 50 deg C, 98% RH-D2O | 0.000249 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 60 deg C, 68% RH | 1.43e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 60 deg C, 75% RH | 9.11e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 60 deg C, 85% RH | 1.23e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 60 deg C, 93% RH | 1.73e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 60 deg C, 98% RH | 0.00109 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 60 deg C, 98% RH-D2O | 0.000305 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 70 deg C, 68% RH | 2.31e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 70 deg C, 75% RH | 1.16e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 70 deg C, 85% RH | 2.52e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 70 deg C, 93% RH | 2.79e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 70 deg C, 98% RH | 0.00129 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 70 deg C, 98% RH-D2O | 0.000387 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 80 deg C, 68% RH | 5.21e-06 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 80 deg C, 75% RH | 2.3e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 80 deg C, 85% RH | 4.25e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 80 deg C, 93% RH | 7.81e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 80 deg C, 98% RH | 0.00208 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 80 deg C, 98% RH-D2O | 0.000455 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 90 deg C, 68% RH | 1.94e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 90 deg C, 75% RH | 5.59e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 90 deg C, 85% RH | 7.82e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 90 deg C, 93% RH | 0.000167 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 90 deg C, 98% RH | 0.00278 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 90 deg C, 98% RH-D2O | 0.000554 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 100 deg C, 68% RH | 3.42e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 100 deg C, 75% RH | 8.78e-05 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 100 deg C, 85% RH | 0.000196 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 100 deg C, 93% RH | 0.000496 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 100 deg C, 98% RHMarked as a best value within this paper | 0.00386 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| DUT-67(Hf) proton conductivity at 100 deg C, 98% RH-D2O | 0.000822 S cm^-1 | — | — | SI Table Exact Reported | SI p002 · Table S2 · Table S2 |
| Table 1 comparison entry for DUT-67(Hf)Marked as a best value within this paper | 3.86 x 10^-3 S cm^-1; Table 1 condition appears as 50 deg C and 98% RH | — | — | Table Exact Reported | 3040 · Table 1 · Table 1 |