Researchers have successfully fabricated a ZrCo alloy with a single cubic B2 phase to investigate the accurate isotope effect. The absorption kinetics of hydrogen isotopes showed no distinct difference in both absorption capacity and rate. The negligible kinetic isotope effect for absorption was attributed to the substantial driving force from system pressure and the close-packed crystal plane in the cubic B2 phase.
Differential scanning calorimetry, temperature programmed desorption, and thermal desorption spectroscopy were used to evaluate the kinetic isotope effect for desorption. The results indicated a significant kinetic isotope effect for desorption, with different peak temperatures and activation energies between hydride and deuteride.
To mitigate the isotope effect during desorption, a local coordination design strategy was proposed, and Ti-Pd co-doping was implemented in a ZrCo alloy. The Zr0.8Ti0.2Co0.8Pd0.2 alloy showed improved stability and reduced isotope separation during desorption, leading to a significant enhancement in cycling stability.
The synergistic effect of Ti-Pd co-doping was found to narrow the temperature gap between thermodynamic stability and isotope effect, contributing to precise isotope supply and enhanced cycling stability of the alloy. The study highlights the importance of isotopic composition control in isotope storage and delivery materials for nuclear fusion applications.