Fig. 2: Thermodynamic isotope effect of ZrCo alloy and harmonic oscillator model.
From: Isotope engineering achieved by local coordination design in Ti-Pd co-doped ZrCo-based alloys

a PCIs of ZrCo alloy for protium absorption and desorption which are represented by open and solid legends, respectively. b Van′t Hoff plot of ZrCo alloy for protium/deuterium absorption and desorption. c Schematic illustration of the potential well curves for molecular and interstitial isotopes. d Dependence of separation factor α on the temperature and interstitial vibration energy ћωH. e Relationship between the critical temperature Tcr and interstitial vibration energy ћωH for binary isotope mixture.