Hydrogen intercalation of compounds with FeSe and MoS2 layered crystal structures

Abstract

Two compounds with a layered structure of FeSe_0.88 superconductor and MoS₂ semiconductor are intercalated with molecular hydrogen (H₂) and ionized hydrogen (H⁺) formed in a special ion source. In the case of FeSe_0.88, intercalation with hydrogen ions causes a slight increase in the superconducting transition temperature of the compound. It is noteworthy that the temperature of the middle of superconducting transition Т_cm of this system can be a little higher on account of magnetization of the FeSe ferromagnetic phase (in a field up to 0.1 T) being in the contact with it. Hydrogen intercalation of MoS₂ is accompanied by an increase in the weight of the compound, and the lattice parameter c associated with the interlayer distance increases from 12.241(6) to 12.297(5) Å. At the same time, along with the existing van der Waals forces, one observes the emergence of Н bonds, which leads to the formation of MoS₂H_0.38 hydride and to an abrupt change in specific resistance (by an order of magnitude) relative to its value before hydrogen intercalation.