Hydrogen-Assisted Mg Intercalation into 2H-TaS2

Intercalation reactions are highly dependent on the electronic and structural relationships between host and guest materials. It is difficult for divalent ions, such as Mg, to undergo intercalation reactions compared with monovalent cations. However, further development of synthetic techniques for controlling divalent ions is strongly demanded to advance applied chemistry and fundamental physics. In this study, the cointercalation of Mg and H into the transition-metal chalcogenide TaS2 was utilized to obtain bulk polycrystalline Mg x H y TaS2. Introduced H can be extracted via postannealing at approximately 400 degrees C without altering the crystal structure. This study clarified the relationship between superconducting properties and electronic carrier density from the perspectives of calculations and experiments, along with the advantages of using hydride as a multivalent intercalation reaction.